Publications 2015
Publications de l'année 2015 :

A balance between membrane elasticity and polymerization energy sets the shape of spherical clathrin coats
Mohammed Saleem ^{1} Sandrine Morlot ^{1} Annika Hohendahl ^{1} John Manzi ^{2} Martin Lenz ^{3} Aurélien Roux ^{1}
Nature Communications, [London] : Nature Pub. Group, 2015, 6, pp.6249. <10.1038/ncomms7249>
In endocytosis, scaffolding is one of the mechanisms to create membrane curvature by moulding the membrane into the spherical shape of the clathrin cage. However, the impact of membrane elastic parameters on the assembly and shape of clathrin lattices has never been experimentally evaluated. Here, we show that membrane tension opposes clathrin polymerization. We reconstitute clathrin budding in vitro with giant unilamellar vesicles (GUVs), purified adaptors and clathrin. By changing the osmotic conditions, we find that clathrin coats cause extensive budding of GUVs under low membrane tension while polymerizing into shallow pits under moderate tension. High tension fully inhibits polymerization. Theoretically, we predict the tension values for which transitions between different clathrin coat shapes occur. We measure the changes in membrane tension during clathrin polymerization, and use our theoretical framework to estimate the polymerization energy from these data. Our results show that membrane tension controls clathrinmediated budding by varying the membrane budding energy.
 1. Department of Biochemistry
 2. PCC  PhysicoChimieCurie
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

A statistical model of intrachromosome contact maps
L. Nazarov ^{1} M. V. Tamm ^{1, 2} S. K. Nechaev ^{2, 3, 4} V. A. Avetisov ^{2, 5}
Soft Matter, Royal Society of Chemistry, 2015, pp.1019
The statistical properties of intrachromosome maps obtained by a genomewide chromosome conformation capture method (HiC) are described in the framework of the hierarchical crumpling model of heteropolymer chain with quenched disorder in the primary sequence. We conjecture that the observed HiC maps are statistical averages over many different ways of hierarchical genome folding, and show that the existence of quenched primary structure coupled with hierarchical folding can induce the observed fine structure of intrachromosome contact maps.
 1. Physics Department
 2. Department of Applied Mathematics
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. P. N. Lebedev Physical Institute
 5. The Semenov Institute of Chemical Physics

AGT, NBurge partitions and W_N minimal models
Vladimir Belavin ^{1, 2} Omar Foda ^{3} Raoul Santachiara ^{4}
Journal of High Energy Physics, Springer, 2015, 10, pp.073
Let ${\mathcal B}^{\, p, \, p^{\prime}, \, {\mathcal H}}_{N, n}$ be a conformal block, with $n$ consecutive channels $\chi_{\i}$, $\i = 1, \cdots, n$, in the conformal field theory $\mathcal{M}^{\, p, \, p^{\prime}}_N \! \times \! \mathcal{M}^{\mathcal{H}}$, where $\mathcal{M}^{\, p, \, p^{\prime}}_N$ is a $\mathcal{W}_N$ minimal model, generated by chiral fields of spin $1, \cdots, N$, and labeled by two coprime integers $p$ and $p^{\prime}$, $1 < p < p^{\prime}$, while $\mathcal{M}^{\mathcal{H}}$ is a free boson conformal field theory. $\mathcal{B}^{\, p, \, p^{\prime}, \mathcal{H}}_{N, n}$ is the expectation value of vertex operators between an initial and a final state. Each vertex operator is labelled by a charge vector that lives in the weight lattice of the Lie algebra $A_{N1}$, spanned by weight vectors $\omega_1, \cdots, \omega_{N1}$. We restrict our attention to conformal blocks with vertex operators whose charge vectors point along $\omega_1$. The charge vectors that label the initial and final states can point in any direction. Following the $\mathcal{W}_N$ AGT correspondence, and using Nekrasov's instanton partition functions without modification, to compute $\mathcal{B}^{\, p, \, p^{\prime}, \mathcal{H}}_{N, n}$, leads to illdefined expressions. We show that restricting the states that flow in the channels $\chi_{\i}$, $\i = 1, \cdots, n$, to states labeled by $N$ partitions that satisfy conditions that we call $N$Burge partitions, leads to welldefined expressions that we identify with $\mathcal{B}^{\, p, \, p^{\prime}, \, \mathcal{H}}_{N, n}$. We check our identification by showing that a specific nontrivial conformal block that we compute, using the $N$Burge conditions satisfies the expected differential equation.
 1. IITP  Institute for Information Transmission Problems
 2. P. N. Lebedev Physical Institute [Moscow]
 3. University of Melbourne
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Algebraic area enclosed by random walks on a lattice
Jean Desbois ^{1}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2015, 48 (42), pp.425001. <10.1088/17518113/48/42/425001>
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Anomalous transport of impurities in inelastic Maxwell gases
Vicente Garzó ^{1} Nagi Khalil ^{2} Emmanuel Trizac ^{3}
European Physical Journal E, EDP Sciences: EPJ, 2015, 38, pp.16
A mixture of dissipative hard grains generically exhibits a breakdown of kinetic energy equipartition. The undriven and thus freely cooling binary problem, in the tracer limit where the density of one species becomes minute, may exhibit an extreme form of this breakdown, with the minority species carrying a finite fraction of the total kinetic energy of the system. We investigate the fingerprint of this nonequilibrium phase transition, akin to an ordering process, on transport properties. The analysis, performed by solving the Boltzmann kinetic equation from a combination of analytical and Monte Carlo techniques, hints at the possible failure of hydrodynamics in the ordered region. As a relevant byproduct of the study, the behaviour of the second and fourthdegree velocity moments is also worked out.
 1. Departamento de Fisica
 2. Universidad de Sevilla [Seville]
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Anticoherence of spin states with point group symmetries
D. Baguette ^{1} F. Damanet ^{1} O. Giraud ^{2} J. Martin ^{1}
Physical Review A, American Physical Society, 2015, 92, pp.052333
We investigate multiqubit permutationsymmetric states with maximal entropy of entanglement. Such states can be viewed as particular spin states, namely anticoherent spin states. Using the Majorana representation of spin states in terms of points on the unit sphere, we analyze the consequences of a pointgroup symmetry in their arrangement on the quantum properties of the corresponding state. We focus on the identification of anticoherent states (for which all reduced density matrices in the symmetric subspace are maximally mixed) associated with pointgroup symmetric sets of points. We provide three different characterizations of anticoherence, and establish a link between point symmetries, anticoherence and classes of states equivalent through stochastic local operations with classical communication (SLOCC). We then investigate in detail the case of small numbers of qubits, and construct infinite families of anticoherent states with pointgroup symmetry of their Majorana points, showing that anticoherent states do exist to arbitrary order.
 1. Institut de Physique Nucléaire, Atomique et de Spectrométrie
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Antiperiodic XXZ chains with arbitrary spins: Complete eigenstate construction by functional equations in separation of variables
G. Niccoli ^{1} V. Terras ^{2}
Letters in Mathematical Physics, Springer Verlag, 2015, 105, pp.989
Generic inhomogeneous integrable XXZ chains with arbitrary spins are studied by means of the quantum separation of variables (SOV) method. Within this framework, a complete description of the spectrum (eigenvalues and eigenstates) of the antiperiodic transfer matrix is derived in terms of discrete systems of equations involving the inhomogeneity parameters of the model. We show here that one can reformulate this discrete SOV characterization of the spectrum in terms of functional TQ equations of Baxter's type, hence proving the completeness of the solutions to the associated systems of Bethetype equations. More precisely, we consider here two such reformulations. The first one is given in terms of Qsolutions, in the form of trigonometric polynomials of a given degree $N_s$, of a oneparameter family of TQ functional equations with an extra inhomogeneous term. The second one is given in terms of Qsolutions, again in the form of trigonometric polynomials of degree $N_s$ but with double period, of Baxter's usual (i.e. without extra term) TQ functional equation. In both cases, we prove the precise equivalence of the discrete SOV characterization of the transfer matrix spectrum with the characterization following from the consideration of the particular class of Qsolutions of the functional TQ equation: to each transfer matrix eigenvalue corresponds exactly one such Qsolution and vice versa, and this Qsolution can be used to construct the corresponding eigenstate.
 1. PhysENS  Laboratoire de Physique de l'ENS Lyon
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Athermal analogue of sheared dense Brownian suspensions
Martin Trulsson ^{1} Mehdi Bouzid ^{2} Jorge Kurchan ^{2} Eric Clément ^{2} Philippe Claudin ^{2} Bruno Andreotti ^{2}
EPL, European Physical Society/EDP Sciences/Società Italiana di Fisica/IOP Publishing, 2015, 111, pp.18001
The rheology of dense Brownian suspensions of hard spheres is investigated numer ically beyond the lowshearrate Newtonian regime. We analyze an athermal analogue of these suspensions, with an effective logarithmic repulsive potential representing the vibrational entropic forces. We show that both systems present the same rheology without adjustable parameters. Moreover, all rheological responses display similar HerschelBulkley relations once the shear stress and the shear rate are respectively rescaled by a characteristic stress scale and by a microscopic reorganization time scale, both related to the normal confining pressure. This pressurecontrolled approach, originally developed for granular flows, reveals a striking physical analogy between the colloidal glass transition and granular jamming.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. PMMH  Physique et mécanique des milieux hétérogenes

Autolocalization in a dipolar exciton system
S. V. Andreev ^{1}
Physical Review B : Condensed matter and materials physics, American Physical Society, 2015, 92, pp.041117
We develop the autolocalization hypothesis suggested recently in [Andreev, Phys. Rev. Lett. 110, 146401 (2013)] to explain the formation of the macroscopically ordered exciton state (MOES) in semiconductor quantum wells [L. V. Butov et al., Nature (London) 418, 751 (2002)]. We argue that the onset of a periodical localizing potential having a macroscopic spatial period is possible in the systems where in addition to longrange dipolar repulsion the excitons exhibit resonant pairing at short distances. Our theory suggests, that the central incoherent part of each condensate in the MOES may represent a novel quantum molecular phase, which was predicted and discussed theoretically several years ago in the context of resonant Bose superfluids.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Blast dynamics in a dissipative gas
Matthieu Barbier ^{1} Dario Villamaina ^{2} Emmanuel Trizac ^{3}
Physical Review Letters, American Physical Society, 2015, 115, pp.214301
The blast caused by an intense explosion has been extensively studied in conservative fluids, where the Taylorvon NeumannSedov hydrodynamic solution is a prototypical example of selfsimilarity driven by conservation laws. In dissipative media however, energy conservation is violated, yet a distinctive selfsimilar solution appears. It hinges on the decoupling of random and coherent motion permitted by a broad class of dissipative mechanisms. This enforces a peculiar layered structure in the shock, for which we derive the full hydrodynamic solution, validated by a microscopic approach based on Molecular Dynamics simulations. We predict and evidence a succession of temporal regimes, as well as a longtime corrugation instability, also selfsimilar, which disrupts the blast boundary. These generic results may apply from astrophysical systems to granular gases, and invite further crossfertilization between microscopic and hydrodynamic approaches of shockwaves.
 1. Department of Ecology and Evolutionary Biology [Princeton]
 2. LPTENS  Laboratoire de Physique Théorique de l'ENS
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Branching Brownian Motion Conditioned on Particle Numbers
Kabir Ramola ^{1} Satya N. Majumdar ^{1} Gregory Schehr ^{1}
Chaos, Solitons and Fractals, Elsevier, 2015, 74, pp.79
We study analytically the order and gap statistics of particles at time $t$ for the one dimensional branching Brownian motion, conditioned to have a fixed number of particles at $t$. The dynamics of the process proceeds in continuous time where at each time step, every particle in the system either diffuses (with diffusion constant $D$), dies (with rate $d$) or splits into two independent particles (with rate $b$). We derive exact results for the probability distribution function of $g_k(t) = x_k(t)  x_{k+1}(t)$, the distance between successive particles, conditioned on the event that there are exactly $n$ particles in the system at a given time $t$. We show that at large times these conditional distributions become stationary $P(g_k, t \to \inftyn) = p(g_kn)$. We show that they are characterised by an exponential tail $p(g_kn) \sim \exp[\sqrt{\frac{b  d}{2 D}} ~g_k]$ for large gaps in the subcritical ($b < d$) and supercritical ($b > d$) phases, and a power law tail $p(g_k) \sim 8\left(\frac{D}{b}\right){g_k}^{3}$ at the critical point ($b = d$), independently of $n$ and $k$. Some of these results for the critical case were announced in a recent letter [K. Ramola, S. N. Majumdar and G. Schehr, Phys. Rev. Lett. 112, 210602 (2014)].
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Capacitance and charge relaxation resistance of chaotic cavities – Joint distribution of two linear statistics in the Laguerre ensemble of random matrices
Aurélien Grabsch ^{1} Christophe Texier ^{2}
Europhysics letters  EPL, Association européenne de physique, 2015, 109, pp.50004
We consider the AC transport in a quantum RC circuit made of a coherent chaotic cavity with a top gate. Within a random matrix approach, we study the joint distribution for the mesoscopic capacitance $C_\mu=(1/C+1/C_q)^{1}$ and the charge relaxation resistance $R_q$, where $C$ is the geometric capacitance and $C_q$ the quantum capacitance. We study the limit of a large number of conducting channels $N$ with a Coulomb gas method. We obtain $\langle R_q\rangle\simeq h/(Ne^2)=R_\mathrm{dc}$ and show that the relative fluctuations are of order $1/N$ both for $C_q$ and $R_q$, with strong correlations $\langle \delta C_q\delta R_q\rangle/\sqrt{\langle \delta C_q^2\rangle\,\langle \delta R_q^2\rangle}\simeq+0.707$. The detailed analysis of large deviations involves a second order phase transition in the Coulomb gas. The two dimensional phase diagram is obtained.
 1. ENS Cachan  École normale supérieure  Cachan
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Casimir–Polder force between anisotropic nanoparticles and gently curved surfaces
Giuseppe Bimonte ^{1} Thorsten Emig ^{2} Mehran Kardar ^{3}
Physical Review D, American Physical Society, 2015, 92, pp.025028
The CasimirPolder interaction between an anisotropic particle and a surface is orientation dependent. We study novel orientational effects that arise due to curvature of the surface for distances much smaller than the radii of curvature by employing a derivative expansion. For nanoparticles we derive a general short distance expansion of the interaction potential in terms of their dipolar polarizabilities. Explicit results are presented for nanospheroids made of SiO$_2$ and gold, both at zero and at finite temperatures. The preferred orientation of the particle is strongly dependent on curvature, temperature, as well as material properties.
 1. INFN, Sezione di Napoli  Istituto Nazionale di Fisica Nucleare, Sezione di Napoli
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. Department of Physics

Columnar order and AshkinTeller criticality in mixtures of hardsquares and dimers
Kabir Ramola ^{1} Kedar Damle ^{2} Deepak Dhar ^{2}
Physical Review Letters, American Physical Society, 2015, 114, pp.190601
Particles with only hardcore interactions can exhibit interesting highdensity phases. The cases of particles in the shape of $2\times2$ squares, and $2\times 1$ dimers on a square lattice have been studied for a long time. Here, we study the interesting and more general problem of a mixture of such dimers and squares. In the fullypacked limit of no vacancies, increasing the fraction of squares enhances the powerlaw columnar (stripe) order present in the pure dimer limit and eventually leads to a KosterlitzThoulesstype (KT) phase transition to a squarerich phase with longrange columnar order. With vacancies allowed, the entire phase boundary between this columnar ordered phase and the lowdensity fluid phase has continuously varying exponents and is in the AshkinTeller universality class. These results, which we confirm by MonteCarlo simulations, make explicit the AshkinTeller nature of the densitydriven transition in the $2\times 2$ hardsquare gas.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Tata Institute of Fundamental Research

Comment on « Linear wave dynamics explains observations attributed to darksolitons in a polariton quantum fluid »
A. Amo ^{1} J. Bloch ^{1} A. Bramati ^{2} I. Carusotto ^{3} C. Ciuti ^{4} B. DeveaudPlédran ^{5} E. Giacobino ^{2} G. Grosso ^{6} A. Kamchatnov ^{7} Guillaume Malpuech ^{8} N. Pavloff ^{9} S. Pigeon ^{10} D. Sanvitto ^{11} D. D. Solnyshkov ^{8}
Physical Review Letters, American Physical Society, 2015, 115, pp.089401
In a recent preprint (arXiv:1401.1128v1) Cilibrizzi and coworkers report experiments and simulations showing the scattering of polaritons against a localised obstacle in a semiconductor microcavity. The authors observe in the linear excitation regime the formation of density and phase patterns reminiscent of those expected in the nonlinear regime from the nucleation of dark solitons. Based on this observation, they conclude that previous theoretical and experimental reports on dark solitons in a polariton system should be revised. Here we comment why the results from Cilibrizzi et al. take place in a very different regime than previous investigations on dark soliton nucleation and do not reproduce all the signatures of its rich nonlinear phenomenology. First of all, Cilibrizzi et al. consider a particular type of radial excitation that strongly determines the observed patterns, while in previous reports the excitation has a planewave profile. Most importantly, the nonlinear relation between phase jump, soliton width and fluid velocity, and the existence of a critical velocity with the timedependent formation of vortexantivortex pairs are absent in the linear regime. In previous reports about dark soliton and halfdark soliton nucleation in a polariton fluid, the distinctive dark soliton physics is supported both by theory (analytical and numerical) and experiments (both continuous wave and pulsed excitation).
 1. LPN  Laboratoire de photonique et de nanostructures
 2. LKB (Jussieu)  Laboratoire Kastler Brossel
 3. INOCNR BEC Center and Dipartimento di Fisica
 4. MPQ  Matériaux et Phénomènes Quantiques
 5. EPFL  Ecole Polytechnique Fédérale de Lausanne
 6. Massachusetts Institute of Technology
 7. Institute of Spectroscopy
 8. Institut Pascal [Aubiere]
 9. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 10. Queen's University Belfast [Belfast]
 11. ISACCNR  ISACCNR Lecce Section

Condensate formation in a zerorange process with random site capacities
Shamik Gupta ^{1, 2, 3} Mustansir Barma ^{4}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2015, pp.P07018
We study the effect of quenched disorder on the zerorange process (ZRP), a system of interacting particles undergoing biased hopping on a onedimensional periodic lattice, with the disorder entering through random capacities of sites. In the usual ZRP, sites can accommodate an arbitrary number of particles, and for a class of hopping rates and high enough density, the steady state exhibits a condensate which holds a finite fraction of the total number of particles. The sites of the disordered zerorange process considered here have finite capacities chosen randomly from the Pareto distribution. From the exact steady state measure of the model, we identify the conditions for condensate formation, in terms of parameters that involve both interactions (through the hop rates) and randomness (through the distribution of the site capacities). Our predictions are supported by results obtained from a direct numerical sampling of the steady state and from Monte Carlo simulations. Our study reveals that for a given realization of disorder, the condensate can relocate on the subset of sites with largest capacities. We also study sampletosample variation of the critical density required to observe condensation, and show that the corresponding distribution obeys scaling, and has a Gaussian or a Levystable form depending on the values of the relevant parameters.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Dipartimento di Fisica e Astronomia, Universit'a di Firenze
 3. MPIPKS  Max Planck Institute für Physik Komplexer System, Dresden
 4. Department of Theoretical Physics

Conformal invariance of loop ensembles under KardarParisiZhang dynamics
Xiangyu Cao ^{1} Alberto Rosso ^{1} Raoul Santachiara ^{1}
EPL, European Physical Society, 2015, 111, pp.16001
We study scaling properties of the honeycomb fully packed loop ensemble associated with a lozenge tiling model of rough surface, when the latter is driven out of equilibrium by KardarParisiZhang (KPZ) type dynamics. We show numerically that conformal invariance and signatures of critical percolation appear in the stationary KPZ state. In terms of the twocomponent Coulomb gas description of the EdwardsWilkinson stationary state, our finding is understood as the invariance of one component under the effect of the nonlinear KPZ term. On the other hand, we show a breaking of conformal invariance when the level lines of the other component are considered.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Connecting local active forces to macroscopic stress in elastic media
Pierre Ronceray ^{1} Martin Lenz ^{1}
Soft Matter, Royal Society of Chemistry, 2015, 11, pp.1597
In contrast with ordinary materials, living matter drives its own motion by generating active, outofequilibrium internal stresses. These stresses typically originate from localized active elements embedded in an elastic medium, such as molecular motors inside the cell or contractile cells in a tissue. While many largescale phenomenological theories of such active media have been developed, a systematic understanding of the emergence of stress from the local forcegenerating elements is lacking. In this paper, we present a rigorous theoretical framework to study this relationship. We show that the medium's macroscopic active stress tensor is equal to the active elements' force dipole tensor per unit volume in both continuum and discrete linear homogeneous media of arbitrary geometries. This relationship is conserved on average in the presence of disorder, but can be violated in nonlinear elastic media. Such effects can lead to either a reinforcement or an attenuation of the active stresses, giving us a glimpse of the ways in which nature might harness microscopic forces to create active materials.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Convex hull of a Brownian motion in confinement
M. Chupeau ^{1} O. Bénichou ^{1} S. N. Majumdar ^{2}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2015, 91, pp.050104
We study the effect of confinement on the mean perimeter of the convex hull of a planar Brownian motion, defined as the minimum convex polygon enclosing the trajectory. We use a minimal model where an infinite reflecting wall confines the walk to its one side. We show that the mean perimeter displays a surprising minimum with respect to the starting distance to the wall and exhibits a nonanalyticity for small distances. In addition, the mean span of the trajectory in a fixed direction {$\theta \in ]0,\pi/2[$}, which can be shown to yield the mean perimeter by integration over $\theta$, presents these same two characteristics. This is in striking contrast with the one dimensional case, where the mean span is an increasing analytical function. The nonmonotonicity in the 2D case originates from the competition between two antagonistic effects due to the presence of the wall: reduction of the space accessible to the Brownian motion and effective repulsion.
 1. LPTMC  Laboratoire de Physique Théorique de la Matière Condensée
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Convex Hulls of Random Walks: LargeDeviation Properties
Gunnar Claussen ^{1} Alexander K. Hartmann ^{1} Satya N. Majumdar ^{2}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2015, 91, pp.052104
We study the convex hull of the set of points visited by a twodimensional random walker of T discrete time steps. Two natural observables that characterize the convex hull in two dimensions are its perimeter L and area A. While the mean perimeter
 1. Institut für Physik
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Critical behavior in topological ensembles
K. Bulycheva ^{1, 2} A. Gorsky ^{2, 3} S. Nechaev ^{4, 5}
Physical Review D, American Physical Society, 2015, 92, pp.105006
We consider the relation between three physical problems: 2D directed lattice random walks, ensembles of $T_{n,n+1}$ torus knots, and instanton ensembles in 5D SQED with one compact dimension in $\Omega$ background and with 5D ChernSimons term at the level one. All these ensembles exhibit the critical behavior typical for the "area+length+corners" statistics of grand ensembles of 2D directed paths. Using the combinatorial description, we obtain an explicit expression of the generating function for $q$Narayana numbers which amounts to the new critical behavior in the ensemble of $T_{n,n+1}$ torus knots and in the ensemble of instantons in 5D SQED. Depending on the number of the nontrivial fugacities, we get either the critical point, or cascade of critical lines and critical surfaces. In the 5D gauge theory the phase transition is of the 3rd order, while in the ensemble of paths and ensemble of knots it is typically of the 1st order. We also discuss the relation with the integrable models.
 1. DPPU  Department of Physics,Princeton University
 2. IITP  Institute for Information Transmission Problems
 3. MIPT  Moscow Institute of Physics and Technology [Moscow]
 4. P. N. Lebedev Physical Institute [Moscow]
 5. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Critical Casimir Force between Inhomogeneous Boundaries
Jerome Dubail ^{1} Raoul Santachiara ^{2} Thorsten Emig ^{3, 2}
EPL, European Physical Society/EDP Sciences/Società Italiana di Fisica/IOP Publishing, 2015, 112, pp.66004
To study the critical Casimir force between chemically structured boundaries immersed in a binary mixture at its demixing transition, we consider a strip of Ising spins subject to alternating fixed spin boundary conditions. The system exhibits a boundary induced phase transition as function of the relative amount of up and down boundary spins. This transition is associated with a sign change of the asymptotic force and a diverging correlation length that sets the scale for the crossover between different universal force amplitudes. Using conformal field theory and a mapping to Majorana fermions, we obtain the universal scaling function of this crossover, and the force at short distances.
 1. IJL  Institut Jean Lamour
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. Massachussetts Institute of Technology

Criticality in the approach to failure in granular materials and amorphous solids
Jie Lin ^{1} Thomas Gueudré ^{2} Alberto Rosso ^{3} Matthieu Wyart ^{4}
Physical Review Letters, American Physical Society, 2015, 115, pp.168001
Failure of amorphous solids is fundamental to various phenomena, including landslides and earthquakes. Recent experiments indicate that highly plastic regions form elongated structures that are especially apparent near the maximal shear stress $\Sigma_{\max}$ where failure occurs. This observation suggested that $\Sigma_{\max}$ acts as a critical point where the length scale of those structures diverges, possibly causing macroscopic transient shear bands. Here we argue instead that the entire solid phase ($\Sigma<\Sigma_{\max}$) is critical, that plasticity always involves systemspanning events, and that their magnitude diverges at $\Sigma_{\max}$ independently of the presence of shear bands. We relate the statistics and fractal properties of these rearrangements to an exponent $\theta$ that captures the stability of the material, which is observed to vary continuously with stress, and we confirm our predictions in elastoplastic models.
 1. Center for Soft Matter Research
 2. DISAT  Department of Applied Science and Technology
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. Institute of Theoretical Physics

Crosstalk in host–parasite associations: What do past and recent proteomics approaches tell us?
Chérif Chetouhi ^{1} Johan Panek ^{2} Ludovic Bonhomme ^{3} Hicham ElalaouiCatherine Texier ^{4} Thierry Langin ^{1} Charissa De BekkerSerge Urbach ^{5, 6, 7} Edith Demettre ^{6} Dorothée Missé ^{8} Philippe Holzmuller ^{9} David P. HughesAndreas Zanzoni ^{10} Christine Brun ^{11, 10} David G. Biron ^{12}
Infection, Genetics and Evolution, 2015, 33, pp.84  94. <10.1016/j.meegid.2015.04.015>
A crosstalk in hostparasite associations begins when a host encounters a parasite. For many hostparasite relationships, this crosstalk has been taking place for hundreds of millions of years. The coevolution of hosts and parasites, the familiar 'arms race' results in fascinating adaptations. Over the years, hostparasite interactions have been studied extensively from both the host and parasitic point of view. Proteomics studies have led to new insights into hostparasite crosstalk and suggest that the molecular strategies used by parasites attacking animals and plants share many similarities. Likewise, animals and plants use several common molecular tactics to counter parasite attacks. Based on proteomics surveys undertaken since the postgenomic era, a synthesis is presented on the molecular strategies used by intra and extracellular parasites to invade and create the needed habitat for growth inside the host, as well as strategies used by hosts to counter these parasite attacks. Pitfalls in deciphering hostparasite crosstalk are also discussed. To conclude, helpful advice is given with regard to new directions that are needed to discover the generic and specific molecular strategies used by the host against parasite invasion as well as by the parasite to invade, survive, and grow inside their hosts, and to finally discover parasitic molecular signatures associated with their development.
 1. GDEC  Génétique Diversité et Ecophysiologie des Céréales
 2. ASCR  Czech Academy of Sciences [Prague]
 3. SMiLES  Spectroscopie, Modélisation, Interfaces pour L'Environnement et la Santé
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 5. Faculty of Sciences, University of Montpellier, Montpellier, France
 6. IGF  Institut de Génomique Fonctionnelle
 7. Functional Proteomics Platform, Institute of Functional Genomics, Montpellier, France
 8. MIVEGEC  Laboratoire de ParasitologieMycologie, Montpellier
 9. CMAEE  Contrôle des maladies animales exotiques et émergentes [Montpellier]
 10. TAGC  Technologies avancées pour le génôme et la clinique
 11. CNRS  Centre National de la Recherche Scientifique
 12. UMR 6023

Direct observation of singleelectron solitons and Friedel oscillations in a quasione dimensional material with incommensurate chargedensity waves
Christophe Brun ^{1} Serguei Brazovskii ^{2} ZhaoZhong Wang ^{3} Pierre Monceau ^{4}
Physica B: Condensed Matter, Elsevier, 2015, 460 (SI), pp.8892. <10.1016/j.physb.2014.11.046>
We have performed scanning tunneling microscopy experiments in the quasione dimensional charge density wave (CDW) system NbSe3, where we could image and study in detail individual solitons corresponding to the selftrapping of a single electron. Our analysis shows that the type of soliton we observed is an ``Amplitude Soliton'', characterized by a vanishing CDW amplitude at the soliton center and by a pishift of its phase along the chain direction. Pairs of solitons or multiple solitons were also observed. Such observations could be made only in the hightemperature COW phase. Additionally, onedimensional Friedel oscillations around charged defects could also be imaged and are found to be superimposed to the COW. The distinction between amplitude solitons and Friedel oscillations can be made without any ambiguity. (C) 2014 Elsevier B.V. All rights reserved.
 1. INSP  Institut des Nanosciences de Paris
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. LPN  Laboratoire de photonique et de nanostructures
 4. MagSup

Direct summation of dipoledipole interactions using the Wolf formalism
Björn Stenqvist ^{1} Martin Trulsson ^{2} Alexei I. Abrikosov ^{3} Mikael Lund ^{1}
Journal of Chemical Physics, American Institute of Physics, 2015, 143 (1), pp.014109. <10.1063/1.4923001>
 1. Department of Theoretical Chemistry
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. Department of Physical Chemistry 1

Dynamic messagepassing equations for models with unidirectional dynamics
Andrey Y. Lokhov ^{1} Marc Mézard ^{2, 1} Lenka Zdeborová ^{3}
Physical Review E, American Physical Society, 2015, 91, pp.012811
Understanding and quantifying the dynamics of disordered outofequilibrium models is an important problem in many branches of science. Using the dynamic cavity method on time trajectories, we construct a general procedure for deriving the dynamic messagepassing equations for a large class of models with unidirectional dynamics, which includes the zerotemperature random field Ising model, the susceptibleinfectedrecovered model, and rumor spreading models. We show that unidirectionality of the dynamics is the key ingredient that makes the problem solvable. These equations are applicable to single instances of the corresponding problems with arbitrary initial conditions, and are asymptotically exact for problems defined on locally treelike graphs. When applied to realworld networks, they generically provide a good analytic approximation of the real dynamics.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. ENS  Ecole Normale Supérieure
 3. IPHT  Institut de Physique Théorique (ex SPhT)

Dynamic nuclear polarization and the paradox of Quantum Thermalization
Andrea De Luca ^{1} Alberto Rosso ^{1}
Physical Review Letters, American Physical Society, 2015, 115, pp.080401
Dynamic Nuclear Polarization (DNP) is to date the most effective technique to increase the nuclear polarization up to a factor $100,000$ opening disruptive perspectives for medical applications. In DNP, the nuclear spins are driven to an  out of equilibrium  hyperpolarized state by microwave saturation of the electron spins in interaction with them. Here we show that the electron dipolar interactions compete with the local magnetic fields resulting in two distinct dynamical phases: for strong interactions the electron spins equilibrate to an extremely low effective temperature that boosts DNP efficiency. For weak interaction this spin temperature is not defined and the polarization profile has an 'hole burning' shape characteristic of the non interacting case. The study of the manybody eigenstates reveals that these two phases are intimately related to the problem of thermalization in closed quantum systems where breaking of ergodicity is expected varying the strength of the interactions.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Dynamical transition in the temporal relaxation of stochastic processes under resetting
Satya N. Majumdar ^{1} Sanjib Sabhapandit ^{2} Gregory Schehr ^{1}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2015, 91, pp.052131
A stochastic process, when subject to resetting to its initial condition at a constant rate, generically reaches a nonequilibrium steady state. We study analytically how the steady state is approached in time and find an unusual relaxation mechanism in these systems. We show that as time progresses, an inner core region around the resetting point reaches the steady state, while the region outside the core is still transient. The boundaries of the core region grow with time as power laws at late times. Alternatively, at a fixed spatial point, the system undergoes a dynamical transition from the transient to the steady state at a characteristic space dependent timescale $t^*(x)$. We calculate analytically in several examples the large deviation function associated with this spatiotemporal fluctuation and show that generically it has a second order discontinuity at a pair of critical points characterizing the edges of the inner core. Our results are verified in the numerical simulations of several models, such as simple diffusion and fluctuating onedimensional interfaces.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Raman Research Institute

Edge structure of graphene monolayers in the {\nu} = 0 quantum Hall state
Angelika Knothe ^{1, 2} Thierry Jolicoeur ^{2}
Physical Review B : Condensed matter and materials physics, American Physical Society, 2015, 92, pp.165110
Monolayer graphene at neutrality in the quantum Hall regime has many competing ground states with various types of ordering. The outcome of this competition is modified by the presence of the sample boundaries. In this paper we use a HartreeFock treatment of the electronic correlations allowing for spacedependent ordering. The edge influence is modeled by a simple perturbative effective magnetic field in valley space. We find that all phases found in the bulk of the sample, ferromagnetic, canted antiferromagnetic, chargedensity wave and Kekul$\'e$ distortion are smoothly connected to a Kekul$\'e$distorted edge. The singleparticle excitations are computed taking into account the spatial variation of the order parameters. An eventual metalinsulator transition as a function of the Zeeman energy is not simply related to the type of bulk order.
 1. University of Freiburg [Freiburg]
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Effect of Curvature and Confinement on the CasimirPolder Interaction
Pablo RodriguezLopez ^{1} Thorsten Emig ^{1} Ehsan Noruzifar ^{2} Roya Zandi ^{3}
Physical Review A, American Physical Society, 2015, pp.012516
Modifications of CasimirPolder interactions due to confinement inside a cylindrical cavity and due to curvature in and outside the cavity are studied. We consider a perfectly conducting cylindrical shell with a single particle (atom or macroscopic sphere) located next to its interior or exterior surface, or two atoms placed inside the shell. By employing the scattering approach, we obtain the particlecavity interaction and the modification of the twoparticle interaction due to the cavity. We consider both retardation and thermal effects. While for the atoms a dipole description is sufficient, for the macroscopic sphere we sum (numerically) over many multipole fluctuations to compute the interaction at short separations. In the latter limit we compare to the proximity approximation and a gradient expansion and find agreement. Our results indicate an confinement induced suppression of the force between atoms. General criteria for suppression and enhancement of Casimir interactions due to confinement are discussed.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Department of Chemistry and Biochemistry
 3. Department of Physics and Astronomy

Effective charge of cylindrical and spherical colloids immersed in an electrolyte: the quasiplanar limit
L. Samaj ^{1, 2} E. Trizac ^{2}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2015, 48, pp.265003
We consider the nonlinear PoissonBoltzmann theory for a single cylindrical or spherical macroion in symmetric 1:1, together with asymmetric 1:2 and 2:1 electrolytes. We focus on the regime where $\kappa a $, the ratio of the macroion radius $a$ over the inverse Debye length in the bulk electrolyte, is large. Analyzing the structure of the analytical expansion emerging from a multiple scale analysis, we uncover a hidden structure for the electrostatic potential. This structure, which appears after a heuristic resummation, suggests a new and convenient expansion scheme that we present and work out in detail. We show that novel exact results can thereby be obtained, in particular pertaining to effective charge properties, in complete agreement with the direct numerical solution to the problem.
 1. Institute of Physics, Slovak Academy of Sciences
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Effective Langevin equations for constrained stochastic processes
Satya N. Majumdar ^{1} Henri Orland ^{2}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2015, pp.P06039
We propose a novel stochastic method to exactly generate Brownian paths conditioned to start at an initial point and end at a given final point during a fixed time $t_{f}$. These paths are weighted with a probability given by the overdamped Langevin dynamics. We show how these paths can be exactly generated by a local stochastic differential equation. The method is illustrated on the generation of Brownian bridges, Brownian meanders, Brownian excursions and constrained OrnsteinUehlenbeck processes. In addition, we show how to solve this equation in the case of a general force acting on the particle. As an example, we show how to generate constrained path joining the two minima of a doublewell. Our method allows to generate statistically independent paths, and is computationally very efficient.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. IPHT  Institut de Physique Théorique  UMR CNRS 3681

Effects of topological constraints on globular polymers
Maxim Imakaev ^{1} Konstantin Tchourine ^{2, 1} Sergei Nechaev ^{3, 4} Leonid Mirny ^{1, 5}
Soft Matter, Royal Society of Chemistry, 2015, 11, pp.665
Topological constraints can affect both equilibrium and dynamic properties of polymer systems, and can play a role in the organization of chromosomes. Despite many theoretical studies, the effects of topological constraints on the equilibrium state of a single compact polymer have not been systematically studied. Here we use simulations to address this longstanding problem. We find that sufficiently long unknotted polymers differ from knotted ones in the spatial and topological states of their subchains. The unknotted globule has subchains that are mostly unknotted and form asymptotically compact $R_G(s) \sim s^{1/3}$ crumples. However, crumples display high fractal dimension of the surface $d_b = 2.8$, forming excessive contacts and interpenetrating each other. We conclude that this topologically constrained equilibrium state resembles a conjectured crumpled globule [Grosberg et al., Journal de Physique, 1988, 49, 2095], but differs from its idealized hierarchy of selfsimilar, isolated and compact crumples.
 1. Department of Physics [Cambridge]
 2. Center for Genomics and Systems Biology, New York University
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. P. N. Lebedev Physical Institute
 5. Institute for Medical Engineering and Science, MIT

Favoured Local Structures in Liquids and Solids: a 3D Lattice Model
Pierre Ronceray ^{1} Peter Harrowell ^{2}
Soft Matter, Royal Society of Chemistry, 2015, 11, pp.3322
We investigate the connection between the geometry of Favoured Local Structures (FLS) in liquids and the associated liquid and solid properties. We introduce a lattice spin model  the FLS model on a facecentered cubic lattice  where this geometry can be arbitrarily chosen among a discrete set of 115 possible FLS. We find crystalline groundstates for all choices of a single FLS. Sampling all possible FLS's, we identify the following trends: i) low symmetry FLS's produce larger crystal unit cells but not necessarily higher energy groundstates, ii) chiral FLS's exhibit to peculiarly poor packing properties, iii) accumulation of FLS's in supercooled liquids is linked to large crystal unit cells, and iv) low symmetry FLS's tend to find metastable structures on cooling.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Faculty of Sciences

FiniteTemperature Free Fermions and the KardarParisiZhang Equation at Finite Time
David S. Dean ^{1} Pierre Le Doussal ^{2} Satya N. Majumdar ^{3} Grégory Schehr ^{3}
Physical Review Letters, American Physical Society, 2015, 114 (11), pp.110402 (15). <10.1103/PhysRevLett.114.110402>
We consider the system of $N$ onedimensional free fermions confined by a harmonic well $V(x) = m\omega^2 {x^2}/{2}$ at finite inverse temperature $\beta = 1/T$. The average density of fermions $\rho_N(x,T)$ at position $x$ is derived. For $N \gg 1$ and $\beta \sim {\cal O}(1/N)$, $\rho_N(x,T)$ is described by a scaling function interpolating between a Gaussian at high temperature, for $\beta \ll 1/N$, and the Wigner semicircle law at low temperature, for $\beta \gg N^{1}$. In the latter regime, we unveil a scaling limit, for $\beta {\hbar \omega}= b N^{1/3}$, where the fluctuations close to the edge of the support, at $x \sim \pm \sqrt{2\hbar N/(m\omega)}$, are described by a limiting kernel $K^{\rm ff}_b(s,s')$ that depends continuously on $b$ and is a generalization of the Airy kernel, found in the Gaussian Unitary Ensemble of random matrices. Remarkably, exactly the same kernel $K^{\rm ff}_b(s,s')$ arises in the exact solution of the KardarParisiZhang (KPZ) equation in 1+1 dimensions at finite time $t$, with the correspondence $t= b^3$.
 1. LOMA  Laboratoire Ondes et Matière d'Aquitaine
 2. LPTENS  Laboratoire de Physique Théorique de l'ENS
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Frictional dynamics of viscoelastic solids driven on a rough surface
Francois P. Landes ^{1, 2} Alberto Rosso ^{2} E. A. Jagla ^{3}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2015, 92, pp.012407
We study the effect of viscoelastic dynamics on the frictional properties of a (mean field) springblock system pulled on a rough surface by an external drive. When the drive moves at constant velocity V, two dynamical regimes are observed: at fast driving, above a critical threshold Vc, the system slides at the drive velocity and displays a friction force with velocity weakening. Below Vc the steady sliding becomes unstable and a stickslip regime sets in. In the slideholdslide driving protocol, a peak of the friction force appears after the hold time and its amplitude increases with the hold duration. These observations are consistent with the frictional force encoded phenomenologically in the rateandstate equations. Our model gives a microscopical basis for such macroscopic description.
 1. The Abdus Salam International Centre for Theoretical Physics
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. Centro Atómico Bariloche and Instituto Balseiro

From statistics of regular treelike graphs to distribution function and gyration radius of branched polymers
Alexander Y. Grosberg ^{1} Sergei K. Nechaev ^{1, 2}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2015, 48, pp.345003
We consider flexible branched polymer, with quenched branch structure, and show that its conformational entropy as a function of its gyration radius $R$, at large $R$, obeys, in the scaling sense, $\Delta S \sim R^2/(a^2L)$, with $a$ bond length (or Kuhn segment) and $L$ defined as an average spanning distance. We show that this estimate is valid up to at most the logarithmic correction for any tree. We do so by explicitly computing the largest eigenvalues of Kramers matrices for both regular and "sparse" 3branched trees, uncovering on the way their peculiar mathematical properties.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. P. N. Lebedev Physical Institute

Gain properties of dyedoped polymer thin films
I. Gozhyk ^{1, 2} M. BoudreauH. Rabbani HaghighiN. Djellali ^{3} S. Forget ^{4} S. Chénais ^{4} C. Ulysse ^{2} A. Brosseau ^{5} R. Pansu ^{5} J.F. AudibertS. GauvinJ. Zyss ^{6} M. Lebental ^{3, 7}
Biophysical Reviews and Letters, World Scientific Publishing, 2015, 92 (21), <10.1103/PhysRevB.92.214202>
 1. Laboratoire Charles Fabry / Lasers
 2. LPN  Laboratoire de photonique et de nanostructures
 3. LPQM  Laboratoire de Photonique Quantique et Moléculaire
 4. LPL  Laboratoire de Physique des Lasers
 5. PPSM  Laboratoire de Photophysique et Photochimie Supramoléculaires et Macromoléculaires
 6. CNET Bagneux  France Telecom, Centre National d'Etudes de Télécommunications, Laboratoire de Bagneux
 7. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Generalized Efimov effect in one dimension
Sergej Moroz ^{1} José P. D'Incao ^{2} Dmitry S. Petrov ^{3}
Physical Review Letters, American Physical Society, 2015, 115, pp.180406
We study a onedimensional quantum problem of two particles interacting with a third one via a scaleinvariant subcritically attractive inverse square potential, which can be realized, for example, in a mixture of dipoles and charges confined to one dimension. We find that above a critical mass ratio, this version of the Calogero problem exhibits the generalized Efimov effect, the emergence of discrete scale invariance manifested by a geometric series of threebody bound states with an accumulation point at zero energy.
 1. Department of physics, University of Colorado
 2. JILA
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Generalized transport coefficients for inelastic Maxwell mixtures under shear flow
Vicente Garzó ^{1} Emmanuel Trizac ^{2}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2015, 92, pp.052202
The Boltzmann equation framework for inelastic Maxwell models is considered to determine the transport coefficients associated with the mass, momentum and heat fluxes of a granular binary mixture in spatially inhomogeneous states close to the simple shear flow. The Boltzmann equation is solved by means of a ChapmanEnskoglike expansion around the (local) shear flow distributions $f_r^{(0)}$ for each species that retain all the hydrodynamic orders in the shear rate. Due to the anisotropy induced by the shear flow, tensorial quantities are required to describe the transport processes instead of the conventional scalar coefficients. These tensors are given in terms of the solutions of a set of coupled equations, which can be analytically solved as functions of the shear rate $a$, the coefficients of restitution $\alpha_{rs}$ and the parameters of the mixture (masses, diameters and composition). Since the reference distribution functions $f_r^{(0)}$ apply for arbitrary values of the shear rate and are not restricted to weak dissipation, the corresponding generalized coefficients turn out to be nonlinear functions of both $a$ and $\alpha_{rs}$. The dependence of the relevant elements of the three diffusion tensors on both the shear rate and dissipation is illustrated in the tracer limit case, the results showing that the deviation of the generalized transport coefficients from their forms for vanishing shear rates is in general significant. A comparison with the previous results obtained analytically for inelastic hard spheres by using Grad's moment method is carried out showing a good agreement over a wide range of values for the coefficients of restitution. Finally, as an application of the theoretical expressions derived here for the transport coefficients, thermal diffusion segregation of an intruder immersed in a granular gas is also studied.
 1. Departamento de Fisica
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

GroundState Statistics of Directed Polymers with heavytailed disorder
Thomas Gueudré ^{1} Pierre Le Doussal ^{1} JeanPhilippe Bouchaud ^{2} Alberto Rosso ^{3}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2015, 91, pp.062110
In this mostly numerical study, we revisit the statistical properties of the ground state of a directed polymer in a $d=1+1$ "hilly" disorder landscape, i.e. when the quenched disorder has powerlaw tails. When disorder is Gaussian, the polymer minimizes its total energy through a collective optimization, where the energy of each visited site only weakly contributes to the total. Conversely, a hilly landscape forces the polymer to distort and explore a larger portion of space to reach some particularly deep energy sites. As soon as the fifth moment of the disorder diverges, this mechanism radically changes the standard "KPZ" scaling behaviour of the directed polymer, and new exponents prevail. After confirming again that the Flory argument accurately predicts these exponent in the taildominated phase, we investigate several other statistical features of the ground state that shed light on this unusual transition and on the accuracy of the Flory argument. We underline the theoretical challenge posed by this situation, which paradoxically becomes even more acute above the upper critical dimension.
 1. LPTENS  Laboratoire de Physique Théorique de l'ENS
 2. CFM  Capital Fund Management
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

High values of disordergenerated multifractals and logarithmically correlated processes
Yan Fyodorov ^{1} Olivier Giraud ^{2}
Chaos, Solitons and Fractals, Elsevier, 2015, 74, pp.15
In the introductory section of the article we give a brief account of recent insights into statistics of high and extreme values of disordergenerated multifractals following a recent work by the first author with P. Le Doussal and A. Rosso (FLR) employing a close relation between multifractality and logarithmically correlated random fields. We then substantiate some aspects of the FLR approach analytically for multifractal eigenvectors in the RuijsenaarsSchneider ensemble (RSE) of random matrices introduced by E. Bogomolny and the second author by providing an ab initio calculation that reveals hidden logarithmic correlations at the background of the disordergenerated multifractality. In the rest we investigate numerically a few representative models of that class, including the study of the highest component of multifractal eigenvectors in the RuijsenaarsSchneider ensemble.
 1. School of Mathematical Sciences [London]
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Impurity Green’s function of a onedimensional Fermigas
O. Gamayun ^{1, 2} A. G. Pronko ^{3} M. B. Zvonarev ^{4}
Nuclear Physics B, Elsevier, 2015, pp.83
We consider a onedimensional gas of spin1/2 fermions interacting through $\delta$function repulsive potential of an arbitrary strength. For the case of all fermions but one having spin up, we calculate timedependent twopoint correlation function of the spindown fermion. This impurity Green's function is represented in the thermodynamic limit as an integral of Fredholm determinants of integrable linear integral operators.
 1. Bogolyubov Institute for Theoretical Physics, 14b Metrolohichna street, Kiev 03680, Ukraine
 2. Department of Physics, Lancaster University
 3. Steklov Mathematical Institute
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Interaction induced decay of a heteronuclear twoatom system
Peng Xu ^{1} Jiaheng Yang ^{2, 1} Min Liu ^{1} Xiaodong He ^{1} Yong Zeng ^{1, 2} Kunpeng Wang ^{1} Jin Wang ^{1, 2} D. J. Papoular ^{3} G. V. Shlyapnikov ^{4, 5, 1, 6} Mingsheng Zhan ^{1}
Nature Communications, Nature Publishing Group, 2015, 6, pp.7803
Twoatom systems in small traps are of fundamental interest, first of all for understanding the role of interactions in degenerate cold gases and for the creation of quantum gates in quantum information processing with singleatom traps. One of the key quantities is the inelastic relaxation (decay) time when one of the atoms or both are in a higher hyperfine state. Here we measure this quantity in a heteronuclear system of $^{87}$Rb and $^{85}$Rb in a micro optical trap and demonstrate experimentally and theoretically the presence of both fast and slow relaxation processes, depending on the choice of the initial hyperfine states. The developed experimental method allows us to single out a particular relaxation process and, in this sense, our experiment is a "superclean platform" for collisional physics studies. Our results have also implications for engineering of quantum states via controlled collisions and creation of twoqubit quantum gates.
 1. Wuhan Institute of Physics and Mathematics
 2. University of Chinese Academy of Sciences, Beijing 100049, China
 3. INOCNR BEC Center and Dipartimento di Fisica
 4. Russian Quantum Center
 5. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 6. Van der Waals  Zeeman Institute

Interference effects in the twodimensional scattering of microcavity polaritons by an obstacle: phase dislocations and resonances
A. M. Kamchatnov ^{1} N. Pavloff ^{2}
European Physical Journal D, EDP Sciences: EPJ, 2015, pp.32
We consider interference effects within the linear description of the scattering of twodimensional microcavity polaritons by an obstacle. The polariton wave may exhibit phase dislocations created by the interference of the incident and the scattered fields. We describe these structures within the general framework of singular optics. We also discuss another type of interference effects appearing due to the formation of (quasi)resonances in the potential of a repulsive obstacle with sharp boundaries. We discuss the relevance of our approach for the description of recent experimental results and propose a criterion for evaluating the importance of nonlinear effects.
 1. Institute of Spectroscopy
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Interplay of curvature and temperature in the CasimirPolder interaction
Giuseppe Bimonte ^{1} Thorsten Emig ^{2}
Journal of Physics: Condensed Matter, IOP Publishing, 2015, 27, pp.214018
We study the CasimirPolder interaction at finite temperatures between a polarizable small, anisotropic particle and a nonplanar surface using a derivative expansion. We obtain the leading and the nexttoleading curvature corrections to the interaction for low and high temperatures. Explicit results are provided for the retarded limit in the presence of a perfectly conducting surface.
 1. INFN, Sezione di Napoli  Istituto Nazionale di Fisica Nucleare, Sezione di Napoli
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Invariant sums of random matrices and the onset of level repulsion
Zdzisław Burda ^{1} Giacomo Livan ^{2} Pierpaolo Vivo ^{3, 4}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2015, pp.P06024
Using a simple rotateandsum procedure, we construct and solve exactly a random matrix model with peculiar features. It is invariant under the standard symmetry groups (orthogonal and unitary) and yet the interaction between eigenvalues is not Vandermondian. The ensemble contains real symmetric or complex hermitian matrices $\mathbf{S}$ of the form $\mathbf{S}=\sum_{i=1}^M \langle \mathbf{O}_i \mathbf{D}_i\mathbf{O}_i^{\mathrm{T}}\rangle$ or $\mathbf{S}=\sum_{i=1}^M \langle \mathbf{U}_i \mathbf{D}_i\mathbf{U}_i^\dagger\rangle$ respectively. The diagonal matrices $\mathbf{D}_i=\mathrm{diag}\{\lambda_1^{(i)},\ldots,\lambda_N^{(i)}\}$ are constructed from real eigenvalues drawn independently from distributions $p^{(i)}(x)$, while the matrices $\mathbf{O}_i$ and $\mathbf{U}_i$ are all orthogonal or unitary and the average $\langle\cdot\rangle$ is performed over the respective group. While the original matrices $\mathbf{D}_i$ do not exhibit level repulsion, the resulting sum $\mathbf{S}$ develops it upon averaging over multiple $(M\geq 2)$ uncorrelated rotations. We focus on the cases where $p^{(i)}(x)$ is A.) a semicircle law, or B.) a Gaussian law for all $i=1,\ldots,M$. For the choice A, in the limit $N\to\infty$ this ensemble appears spectrally indistinguishable from the standard GOE or GUE, having same spectral density, twopoint correlation function, and nearestneighbor spacing distribution $p(s)$ after unfolding. However, working out the case $N=2$ in detail, we uncover a universal (independent of the $p^{(i)}(x)$) but different from WignerDyson behavior as $s\to 0^+$. The generic interaction between eigenvalues of $\mathbf{S}$ is indeed not precisely Vandermondian, despite the rotationally invariant nature of the ensemble, and classical RMT universality is restored only asymptotically. (continue...)
 1. Faculty of Physics and Applied Computer Science, University of Science and Technology AGH
 2. Department of Computer Science
 3. King's College London
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Large time zero temperature dynamics of the spherical p=2spin model of finite size
Yan V. Fyodorov ^{1} Anthony Perret ^{2} Gregory Schehr ^{2}
Journal of Statistical Mechanics: Theory and Experiment, IOP Publishing, 2015, pp.P11017
We revisit the long time dynamics of the spherical fully connected spinglass model, i.e. the spherical $p=2$spin model, when the number of spins $N$ is large but finite. At $T=0$ where the system is in a (trivial) spinglass phase, and on long time scale $t \gtrsim {\cal O}{(N^{2/3})}$ we show that the behavior of physical observables, like the energy, correlation and response functions, is controlled by the density of nearextreme eigenvalues at the edge of the spectrum of the coupling matrix $J$, and are thus non selfaveraging. We show that the late time decay of these observables, once averaged over the disorder, is controlled by new universal exponents which we compute exactly.
 1. School of Mathematical Sciences [London]
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Liouville theory with a central charge less than one
Sylvain Ribault ^{1, *} Raoul Santachiara ^{2}
Journal of High Energy Physics, Springer Verlag (Germany), 2015, pp.109. <10.1007/JHEP08(2015)109>
We determine the spectrum and correlation functions of Liouville theory with a central charge less than (or equal) one. This completes the definition of Liouville theory for all complex values of the central charge. The spectrum is always spacelike, and there is no consistent timelike Liouville theory. We also study the nonanalytic conformal field theories that exist at rational values of the central charge. Our claims are supported by numerical checks of crossing symmetry. We provide Python code for computing Virasoro conformal blocks, and correlation functions in Liouville theory and (generalized) minimal models.
 1. IPHT  Institut de Physique Théorique  UMR CNRS 3681
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Mean perimeter of the convex hull of a random walk in a semiinfinite medium
M. Chupeau ^{1} O. Bénichou ^{1} S. N. Majumdar ^{2}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2015, 92, pp.022145
We study various properties of the convex hull of a planar Brownian motion, defined as the minimum convex polygon enclosing the trajectory, in the presence of an infinite reflecting wall. Recently, in a Rapid Communication [Phys. Rev. E \textbf{91}, 050104(R) (2015)], we announced that the mean perimeter of the convex hull at time $t$, rescaled by $\sqrt{Dt}$, is a nonmonotonous function of the initial distance to the wall. In the present article, we first give all the details of the derivation of this mean rescaled perimeter, in particular its value when starting from the wall and near the wall. We then determine the physical mechanism underlying this surprising nonmonotonicity of the mean rescaled perimeter by analyzing the impact of the wall on two complementary parts of the convex hull. Finally, we provide a further quantification of the convex hull by determining the mean length of the portion of the reflecting wall visited by the Brownian motion as a function of the initial distance to the wall.
 1. LPTMC  Laboratoire de Physique Théorique de la Matière Condensée
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Microrheology to probe nonlocal effects in dense granular flows
Mehdi Bouzid ^{1} Martin Trulsson ^{2} Philippe Claudin ^{1} Eric Clément ^{1} Bruno Andreotti ^{1}
EPL (Europhysics Letters), 2015, 109, pp.24002
A granular material is observed to flow under the Coulomb yield criterion as soon as this criterion is satisfied in a remote but contiguous region of space. We investigate this nonlocal effect using discrete element simulations, in a geometry similar, in spirit, to the experiment of Reddy et al. [PRL 106, 108301 (2011)]: a microrheometer is introduced to determine the influence of a distant shear band on the local rheological behaviour. The numerical simulations recover the dominant features of this experiment: the local shear rate is proportional to that in the shear band and decreases (roughly) exponentially with the distance to the yield conditions. The numerical results are in quantitative agreement with the predictions of the nonlocal rheology proposed by the present authors [PRL 111, 238301 (2013)] and derived from a gradient expansion of the rheology \mu[I]. The consequences of these findings for the dynamical mechanisms controlling nonlocality are finally discussed.
 1. PMMH  Physique et mécanique des milieux hétérogenes
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Minimally entangled typical thermal states versus matrix product purifications for the simulation of equilibrium states and time evolution
Moritz Binder ^{1, 2} Thomas Barthel ^{3, 2}
Physical Review B : Condensed matter and materials physics, American Physical Society, 2015, 92, pp.125119
For the simulation of equilibrium states and finitetemperature response functions of stronglycorrelated quantum manybody systems, we compare the efficiencies of two different approaches in the framework of the density matrix renormalization group (DMRG). The first is based on matrix product purifications. The second, more recent one, is based on socalled minimally entangled typical thermal states (METTS). For the latter, we highlight the interplay of statistical and DMRG truncation errors, discuss the use of selfaveraging effects, and describe schemes for the computation of response functions. For critical as well as gapped phases of the spin1/2 XXZ chain and the onedimensional BoseHubbard model, we assess computation costs and accuracies of the two methods at different temperatures. For almost all considered cases, we find that, for the same computation cost, purifications yield more accurate results than METTS  often by orders of magnitude. The METTS algorithm becomes more efficient only for temperatures well below the system's energy gap. The exponential growth of the computation cost in the evaluation of response functions limits the attainable timescales in both methods and we find that in this regard, METTS do not outperform purifications.
 1. LMU  LudwigMaximiliansUniversität [München]
 2. Duke university [Durham]
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Modelling the emergence of polarity patterns for the intercellular transport of auxin in plants
Silvia Grigolon ^{1} Peter Sollich ^{2} Olivier C. Martin ^{3}
Journal of the Royal Society Interface, Royal Society, 2015, 12, pp.20141223
The hormone auxin is actively transported throughout plants via protein machineries including the dedicated transporter known as PIN. The associated transport is ordered with nearby cells driving auxin flux in similar directions. Here we provide a model of both the auxin transport and of the dynamics of cellular polarisation based on flux sensing. Our main findings are: (i) spontaneous intracellular PIN polarisation arises if PIN recycling dynamics are sufficiently nonlinear, (ii) there is no need for an auxin concentration gradient, and (iii) ordered multicellular patterns of PIN polarisation are favored by molecular noise.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. King's College London
 3. GQE  Génétique Quantitative et Evolution (Génétique Végétale)

Multifractality of quantum wave functions in the presence of perturbations
Rémy Dubertrand ^{1, 2} Ignacio GarciaMata ^{3} Bertrand Georgeot ^{1} Olivier Giraud ^{4} Gabriel Lemarié ^{1} John Martin ^{2}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2015, 92 (3), pp.032914. <http://journals.aps.org/pre/abstract/10.1103/PhysRevE.92.032914>. <10.1103/PhysRevE.92.032914>
We present a comprehensive study of the destruction of quantum multifractality in the presence of perturbations. We study diverse representative models displaying multifractality, including a pseudointegrable system, the Anderson model and a random matrix model. We apply several types of natural perturbations which can be relevant for experimental implementations. We construct an analytical theory for certain cases, and perform extensive largescale numerical simulations in other cases. The data are analyzed through refined methods including double scaling analysis. Our results confirm the recent conjecture that multifractality breaks down following two scenarios. In the first one, multifractality is preserved unchanged below a certain characteristic length which decreases with perturbation strength. In the second one, multifractality is affected at all scales and disappears uniformly for a strong enough perturbation. Our refined analysis shows that subtle variants of these scenarios can be present in certain cases. This study could guide experimental implementations in order to observe quantum multifractality in real systems.
 1. Information et Chaos Quantiques (LPT)
 2. Université de Liège [Liège]
 3. Instituto de Investigaciones Físicas de Mar del Plata
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Nanofriction in cavity quantum electrodynamics
T. Fogarty ^{1} C. Cormick ^{2} H. Landa ^{3} Vladimir M. Stojanović ^{4} E. Demler ^{4} Giovanna Morigi ^{1}
Physical Review Letters, American Physical Society, 2015, 115, pp.233602
The dynamics of cold trapped ions in a highfinesse resonator results from the interplay between the longrange Coulomb repulsion and the cavityinduced interactions. The latter are due to multiple scatterings of laser photons inside the cavity and become relevant when the laser pump is sufficiently strong to overcome photon decay. We study the stationary states of ions coupled with a mode of a standingwave cavity as a function of the cavity and laser parameters, when the typical length scales of the two selforganizing processes, Coulomb crystallization and photonmediated interactions, are incommensurate. The dynamics are frustrated and in specific limiting cases can be cast in terms of the FrenkelKontorova model, which reproduces features of friction in one dimension. We numerically recover the sliding and pinned phases. For strong cavity nonlinearities, they are in general separated by bistable regions where superlubric and stickslip dynamics coexist. The cavity, moreover, acts as a thermal reservoir and can cool the chain vibrations to temperatures controlled by the cavity parameters and by the ions phase. These features are imprinted in the radiation emitted by the cavity, which is readily measurable in stateofart setups of cavity quantum electrodynamics.
 1. Universität des Saarlandes [Saarbrücken]
 2. IFEG  Instituto de Fisica Enrique Gaviola
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. Department of Physics

Nonlocal rheology in dense granular flows
Mehdi Bouzid ^{1} Adrien Izzet ^{1} Martin Trulsson ^{1, 2} Eric Clément ^{1} Philippe Claudin ^{1} Bruno Andreotti ^{1}
European Physical Journal E, EDP Sciences: EPJ, 2015, 38, pp.125
The aim of this article is to discuss the concepts of nonlocal rheology and fluidity, recently introduced to describe dense granular flows. We review and compare various approaches based on different constitutive relations and choices for the fluidity parameter, focusing on the kinetic elastoplastic model introduced by Bocquet et al. [Phys. Rev. Lett \textbf{103}, 036001 (2009)] for soft matter, and adapted for granular matter by Kamrin et al. [Phys. Rev. Lett. \textbf{108}, 178301 (2012)], and the gradient expansion of the local rheology $\mu(I)$ that we have proposed [Phys. Rev. Lett. \textbf{111}, 238301 (2013)]. We emphasise that, to discriminate between these approaches, one has to go beyond the predictions derived from linearisation around a uniform stress profile, such as that obtained in a simple shear cell. We argue that future tests can be based on the nature of the chosen fluidity parameter, and the related boundary conditions, as well as the hypothesis made to derive the models and the dynamical mechanisms underlying their dynamics.
 1. PMMH  Physique et mécanique des milieux hétérogenes
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Occupation times for singlefile diffusion
Olivier Bénichou ^{1} Jean Desbois ^{2}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2015, pp.P03001
We consider a file of identical Brownian particles moving on the same axis x'Ox without crossing each other. They all start from the origin O at time t = 0 and are stopped at some time t. Denoting by T the time spent on the halfline [Ox) by a given particle of the line, we establish analytical formulae for the first two moments 〈T〉 and 〈T2〉. In particular, considering the limit of an infinite number of particles, we get, for the 'middle' particle (J0 is a Bessel function). This result (and also numerical simulations) shows that the distribution of T, though being close to it, is not fully a constant one.
 1. LPTMC  Laboratoire de Physique Théorique de la Matière Condensée
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

On certain functionals of the maximum of Brownian motion and their applications
Anthony Perret ^{1} Alain Comtet ^{1} Satya N. Majumdar ^{1} Gregory Schehr ^{1}
Journal of Statistical Physics, Springer Verlag, 2015, 161, pp.1112
We consider a Brownian motion (BM) $x(\tau)$ and its maximal value $x_{\max} = \max_{0 \leq \tau \leq t} x(\tau)$ on a fixed time interval $[0,t]$. We study functionals of the maximum of the BM, of the form ${\cal O}_{\max}(t)=\int_0^t\, V(x_{\max}  x(\tau)) {\rm d} \tau$ where $V(x)$ can be any arbitrary function and develop various analytical tools to compute their statistical properties. These tools rely in particular on (i) a "counting paths" method and (ii) a pathintegral approach. In particular, we focus on the case where $V(x) = \delta(xr)$, with $r$ a real parameter, which is relevant to study the density of nearextreme values of the BM (the so called density of states), $\rho(r,t)$, which is the local time of the BM spent at given distance $r$ from the maximum. We also provide a thorough analysis of the family of functionals ${T}_{\alpha}(t)=\int_0^t (x_{\max}  x(\tau))^\alpha \, {\rm d}\tau$, corresponding to $V(x) = x^\alpha$, with $\alpha$ real. As $\alpha$ is varied, $T_\alpha(t)$ interpolates between different interesting observables. For instance, for $\alpha =1$, $T_{\alpha = 1}(t)$ is a random variable of the "area", or "Airy", type while for $\alpha=1/2$ it corresponds to the maximum time spent by a ballistic particle through a Brownian random potential. On the other hand, for $\alpha = 1$, it corresponds to the cost of the optimal algorithm to find the maximum of a discrete random walk, proposed by Odlyzko. We revisit here, using tools of theoretical physics, the statistical properties of this algorithm which had been studied before using probabilistic methods. Finally, we extend our methods to constrained BM, including in particular the Brownian bridge, i.e., the Brownian motion starting and ending at the origin.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

On predicting regulatory genes by analysis of functional networks in C. elegans
Olga V. Valba ^{1, 2} Sergei K. Nechaev ^{1, 3, 2} Mark G. Sterken ^{4} L. Basten Snoek ^{4} Jan E. Kammenga ^{4} Olga O. Vasieva ^{5}
BioData Mining, BioMed Central, 2015, 8 (1), pp.33. <10.1186/s1304001500660>
 1. Department of Applied Mathematics
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. P. N. Lebedev Physical Institute [Moscow]
 4. Laboratory of Nematology
 5. Institute of Integrative Biology

Phase diagram of an extended quantum dimer model on the hexagonal lattice
Thiago Schlittler ^{1} Thomas Barthel ^{2, 3} Grégoire Misguich ^{4, *} Julien Vidal ^{1} Rémy Mosseri ^{1}
Physical Review Letters, American Physical Society, 2015, 115, pp.217202. <http://journals.aps.org/prl/pdf/10.1103/PhysRevLett.115.217202>. <10.1103/PhysRevLett.115.217202>
We introduce a quantum dimer model on the hexagonal lattice that, in addition to the standard threedimer kinetic and potential terms, includes a competing potential part counting dimerfree hexagons. The zerotemperature phase diagram is studied by means of quantum Monte Carlo simulations , supplemented by variational arguments. It reveals some new crystalline phases and a cascade of transitions with rapidly changing flux (tilt in the height language). We analyze perturbatively the vicinity of the RokhsarKivelson point, showing that this model has the microscopic ingredients needed for the " devil's staircase " scenario [E. Fradkin et al. Phys. Rev. B 69, 224415 (2004)], and is therefore expected to produce fractal variations of the groundstate flux.
 1. LPTMC  Laboratoire de Physique Théorique de la Matière Condensée
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. Duke university [Durham]
 4. IPHT  Institut de Physique Théorique  UMR CNRS 3681

Phase Diagram of the $\nu=5/2$ Fractional Quantum Hall Effect: Effects of Landau Level Mixing and NonZero Width
Kiryl Pakrouski ^{1} Michael R. Peterson ^{2} Thierry Jolicoeur ^{3} Vito W. Scarola ^{4} Chetan Nayak ^{5, 6} Matthias Troyer ^{1}
Physical Review X, American Physical Society, 2015, 5, pp.029901
Interesting nonAbelian states, e.g., the MooreRead Pfaffian and the antiPfaffian, offer candidate descriptions of the $\nu = 5/2$ fractional quantum Hall state. But the significant controversy surrounding the nature of the $\nu = 5/2$ state has been hampered by the fact that the competition between these and other states is affected by small parameter changes. To study the phase diagram of the $\nu = 5/2$ state we numerically diagonalize a comprehensive effective Hamiltonian describing the fractional quantum Hall effect of electrons under realistic conditions in GaAs semiconductors. The effective Hamiltonian takes Landau level mixing into account to lowestorder perturbatively in $\kappa$, the ratio of the Coulomb energy scale to the cyclotron gap. We also incorporate nonzero width $w$ of the quantum well and subband mixing. We find the ground state in both the torus and spherical geometries as a function of $\kappa$ and $w$. To sort out the nontrivial competition between candidate ground states we analyze the following 4 criteria: its overlap with trial wave functions; the magnitude of energy gaps; the sign of the expectation value of an order parameter for particlehole symmetry breaking; and the entanglement spectrum. We conclude that the ground state is in the universality class of the MooreRead Pfaffian state, rather than the antiPfaffian, for $\kappa < {\kappa_c}(w)$, where ${\kappa_c}(w)$ is a $w$dependent critical value $0.6 \lesssim{\kappa_c}(w)\lesssim 1$. We observe that both Landau level mixing and nonzero width suppress the excitation gap, but Landau level mixing has a larger effect in this regard. Our findings have important implications for the identification of nonAbelian fractional quantum Hall states.
 1. Theoretische Physik
 2. Department of Physics and Astronomy
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. Department of Physics, Virginia tech
 5. Station Q, Microsoft Research
 6. UCSB  Physics Department, University of California at Santa Barbara

Quantum Mechanical Stabilization of a Collapsing BoseBose Mixture
D. S. Petrov ^{1}
Physical Review Letters, American Physical Society, 2015, 115, pp.155302
According to the meanfield theory a condensed BoseBose mixture collapses when the interspecies attraction becomes stronger than the geometrical average of the intraspecies repulsions, $g_{12}^2>g_{11} g_{22}$. We show that instead of collapsing such a mixture gets into a dilute liquidlike droplet state stabilized by quantum fluctuations thus providing a direct manifestation of beyond meanfield effects. We study various properties of the droplet and find, in particular, that in a wide range of parameters its excitation spectrum lies entirely above the particle emission threshold. The droplet thus automatically evaporates itself to zero temperature, the property potentially interesting by itself and from the viewpoint of sympathetic cooling of other systems.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Quantum Signature of Analog Hawking Radiation in Momentum Space
Denis Boiron ^{1} Fabbri Alessandro ^{2} Larré PierreElie ^{3} Nicolas Pavloff ^{4} Christoph I. Westbrook ^{1} Pawel Zin ^{5}
Physical Review Letters., 2015, 115 (2), pp.025301. <http://journals.aps.org/prl/>. <10.1103/PhysRevLett.115.025301>
We consider a sonic analog of a black hole realized in the onedimensional flow of a BoseEinstein condensate. Our theoretical analysis demonstrates that one and twobody momentum distributions accessible by presentday experimental techniques provide clear direct evidence (i) of the occurrence of a sonic horizon, (ii) of the associated acoustic Hawking radiation, and (iii) of the quantum nature of the Hawking process. The signature of the quantum behavior persists even at temperatures larger than the chemical potential.
 1. Laboratoire Charles Fabry / Optique atomique
 2. Centro Fermi  Centro Studi e Ricerche "Enrico Fermi"
 3. Dipartimento di Fisica, Universita di Trento
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 5. National Center for Nuclear Research (NCBJ), Warsaw

Quasi equilibrium construction for the long time limit of glassy dynamics
Silvio Franz ^{1} Giorgio Parisi ^{2} Federico RicciTersenghi ^{2} Pierfrancesco Urbani ^{3}
Journal of Statistical Mechanics: Theory and Experiment, IOP Publishing, 2015, pp.P10010
In this paper we review a recent proposal to understand the long time limit of glassy dynamics in terms of an appropriate Markov Chain. [1]. The advantages of the resulting construction are many. The first one is that it gives a quasi equilibrium description on how glassy systems explore the phase space in the slow relaxation part of their dynamics. The second one is that it gives an alternative way to obtain dynamical equations starting from a dynamical rule that is static in spirit. This provides a way to overcome the difficulties encountered in the short time part of the dynamics where current conservation must be enforced. We study this approach in detail in a prototypical mean field disordered spin system, namely the pspin spherical model, showing how we can obtain the well known equations that describes its dynamics. Then we apply the same approach to structural glasses. We first derive a set of dynamical OrnsteinZernike equations which are very general in nature. Finally we consider two possible closure schemes for them, namely the Hypernetted Chain approximation of liquid theory and a closure of the BBGKY hierarchy that has been recently introduced by G. Szamel. From both approaches we finally find a set of dynamical ModeCoupling like equations that are supposed to describe the system in the long time/slow dynamics regime.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Dipartimento di Fisica and INFM
 3. IPHT  Institut de Physique Théorique  UMR CNRS 3681

Quasiequilibrium in glassy dynamics: a liquid theory approach
Silvio Franz ^{1} Giorgio Parisi ^{2} Pierfrancesco Urbani ^{3, 1}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2015, 48, pp.19FT01
We introduce a quasiequilibrium formalism in the theory of liquids in order to obtain a set of coarse grained long time dynamical equations for the two point density correlation functions. Our scheme allows to use typical approximations devised for equilibrium to study long time glassy dynamics. We study the Hypernetted Chain (HNC) approximation and a recent closure scheme by Szamel. In both cases we get dynamical equations that have the structure of the ModeCoupling (MCT) equations in the long time region. The HNC approach, that was so far used to get equilibrium quantities is thus generalized to a fully consistent scheme where longtime dynamic quantities can also be computed. In the context of this approximation we get an asymptotic description of both equilibrium glassy dynamics at high temperature and of aging dynamics at low temperature. The Szamel approximation on the other hand is shown to lead to the exact Mode Coupling equation of G\"otze for equilibrium dynamics. We clarify the way phase space is sampled according to MCT during dynamical relaxation.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Dipartimento di Fisica and INFM
 3. IPHT  Institut de Physique Théorique  UMR CNRS 3681

Radiative heat transfer in 2D Dirac materials
Pablo RodriguezLopez ^{1} WangKong Tse ^{2} Diego A. R. Dalvit ^{2}
Journal of Physics: Condensed Matter, Institute of Physics: Hybrid Open Access, 2015, 27, pp.214019
We compute the radiative heat transfer between two sheets of 2D Dirac materials, including topological Chern insulators and graphene, within the framework of the local approximation for the optical response of these materials. In this approximation, which neglects spatial dispersion, we derive both numerically and analytically the shortdistance asymptotic of the nearfield heat transfer in these systems, and show that it scales as the inverse of the distance between the two sheets. Finally, we discuss the limitations to the validity of this scaling law imposed by spatial dispersion in 2D Dirac materials.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. LANL  Theorical Division

Random matrices and entanglement entropy of trapped Fermi gases
Pasquale Calabrese ^{1} Pierre Le Doussal ^{2} Satya N. Majumdar ^{3}
Physical Review A, American Physical Society, 2015, pp.012303
We exploit and clarify the use of random matrix theory for the calculation of the entanglement entropy of free Fermi gases. We apply this method to obtain analytic predictions for Renyi entanglement entropies of a onedimensional gas trapped by a harmonic potential in all the relevant scaling regimes. We confirm our findings with accurate numerical calculations obtained by means of an ingenious discretisation of the reduced correlation matrix.
 1. SISSA  International School for Advanced Studies and INFN
 2. LPTENS  Laboratoire de Physique Théorique de l'ENS
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Random walk with random resetting to the maximum position
Satya N. Majumdar ^{1} Sanjib Sabhapandit ^{2} Gregory Schehr ^{1}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2015, 92, pp.052126
We study analytically a simple random walk model on a onedimensional lattice, where at each time step the walker resets to the maximum of the already visited positions (to the rightmost visited site) with a probability $r$, and with probability $(1r)$, it undergoes symmetric random walk, i.e., it hops to one of its neighboring sites, with equal probability $(1r)/2$. For $r=0$, it reduces to a standard random walk whose typical distance grows as $\sqrt{n}$ for large $n$. In presence of a nonzero resetting rate $0
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Raman Research Institute

Record statistics for random walk bridges
Claude Godreche ^{1} Satya N. Majumdar ^{2} Gregory Schehr ^{2}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2015
We investigate the statistics of records in a random sequence $\{x_B(0)=0,x_B(1),\cdots, x_B(n)=x_B(0)=0\}$ of $n$ time steps. The sequence $x_B(k)$'s represents the position at step $k$ of a random walk `bridge' of $n$ steps that starts and ends at the origin. At each step, the increment of the position is a random jump drawn from a specified symmetric distribution. We study the statistics of records and record ages for such a bridge sequence, for different jump distributions. In absence of the bridge condition, i.e., for a free random walk sequence, the statistics of the number and ages of records exhibits a `strong' universality for all $n$, i.e., they are completely independent of the jump distribution as long as the distribution is continuous. We show that the presence of the bridge constraint destroys this strong `all $n$' universality. Nevertheless a `weaker' universality still remains for large $n$, where we show that the record statistics depends on the jump distributions only through a single parameter $0<\mu\le 2$, known as the L\'evy index of the walk, but are insensitive to the other details of the jump distribution. We derive the most general results (for arbitrary jump distributions) wherever possible and also present two exactly solvable cases. We present numerical simulations that verify our analytical results.
 1. IPHT  Institut de Physique Théorique  UMR CNRS 3681
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Reentrant behavior of the breathingmodeoscillation frequency in a onedimensional Bose gas
A. Iu. Gudyma ^{1} G. E. Astrakharchik ^{2} Mikhail B. Zvonarev ^{1}
Physical Review A, American Physical Society, 2015, 92, pp.021601
We calculate the breathing mode frequency $\omega$ in a onedimensional Bose gas confined to a harmonic trap of frequency $\omega_z$. We predict Exciting temporal oscillations of the density distribution is a highprecision method for probing ultracold trapped atomic gases. Interaction effects in their manybody dynamics are particularly puzzling and counterintuitive in one spatial dimension (1D) due to enhanced quantum correlations. We consider 1D quantum Bose gas in a parabolic trap at zero temperature and explain, analytically and numerically, how oscillation frequency depends on the number of particles, their repulsion and the trap strength. We identify the frequency with the energy difference between the ground state and a particular excited state. This way we avoided resolving the dynamical evolution of the system, simplifying the problem immensely. We find an excellent quantitative agreement of our results with the data from the Innsbruck experiment [Science 325, 1224 (2009)].
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Departament de Fisica i Enginyeria Nuclear, Campus Nord B4B5

Relaxation of Loaded ESCRTIII Spiral Springs Drives Membrane Deformation
Nicolas Chiaruttini ^{1} Lorena RedondoMorata ^{2} Adai Colom ^{1, 2, 3} Frédéric Humbert ^{1} Martin Lenz ^{4, *} Simon Scheuring ^{2, *} Aurélien Roux ^{1, 3, *}
Cell, Elsevier, 2015, <10.1016/j.cell.2015.10.017>
13 ESCRTIII is required for lipid membrane remodeling in many cellular processes, from abscission 14 to viral budding and multivesicular body biogenesis. However, how ESCRTIII polymerization 15 generates membrane curvature remains debated. Here we show that Snf7, the main component 16 of ESCRTIII, polymerizes into spirals at the surface of lipid bilayers. When covering the entire 17 membrane surface, these spirals stopped growing when densely packed: they had a polygonal 18 shape, suggesting that lateral compression could deform them. We reasoned that Snf7 spirals 19 could function as spiral springs. By measuring the polymerization energy and the rigidity of Snf7 20 filaments, we showed that they were deformed while growing in a confined area. Furthermore, 21 we observed that the elastic expansion of compressed Snf7 spirals generated an area difference 22 between the two sides of the membrane and thus curvature. This springlike activity underlies the 23 driving force by which ESCRTIII could mediate membrane deformation and fission. 24 2
 1. Biochemistry Department  University of Geneva
 2. BioAFMLab  BIOAFMLAB Bio Atomic Force Microscopy Laboratory
 3. NCCRChemical Biology  Swiss National Centre for Competence in Research Programme Chemical Biology
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Reversing the Critical Casimir force by shape deformation
G. Bimonte ^{1} T. Emig ^{2, 3} M. Kardar ^{4}
Physics Letters B, Elsevier, 2015, 743, pp.138
The exact critical Casimir force between periodically deformed boundaries of a 2D semiinfinite strip is obtained for conformally invariant classical systems. Only two parameters (conformal charge and scaling dimension of a boundary changing operator), along withthe solution of an electrostatic problem, determine the Casimir force, rendering the theory practically applicable to any shape and arrangement. The attraction between any two mirror symmetric objects follows directly from our general result. The possibility of purely shape induced reversal of the force, as well as occurrence of stable equilibrium points, is demonstrated for certain conformally invariant models, including the tricritical Ising model.
 1. INFN, Sezione di Napoli  Istituto Nazionale di Fisica Nucleare, Sezione di Napoli
 2. MSE2  Multiscale Materials Science for Energy and Environment
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. Department of Physics

Screening likecharges in onedimensional Coulomb systems: Exact results
Gabriel Tellez ^{1} Emmanuel Trizac ^{2}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2015, 92, pp.042134
The possibility that likecharges can attract each other under the mediation of mobile counterions is by now well documented experimentally, numerically, and analytically. Yet, obtaining exact results is in general impossible, or restricted to some limiting cases. We work out here in detail a one dimensional model that retains the essence of the phenomena present in higher dimensional systems. The partition function is obtained explicitly, from which a wealth of relevant quantities follow, such as the effective force between the charges or the counterion profile in their vicinity. Isobaric and canonical ensembles are distinguished. The case of two equal charges screened by an arbitrary number $N$ of counterions is first studied, before the more general asymmetric situation is addressed. It is shown that the parity of $N$ plays a key role in the long range physics.
 1. Departamento de Fisica
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Spatial Extent of Branching Brownian Motion
Kabir Ramola ^{1} Satya N. Majumdar ^{1} Gregory Schehr ^{1}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2015, 91, pp.042131
We study the one dimensional branching Brownian motion starting at the origin and investigate the correlation between the rightmost ($X_{\max}\geq 0$) and leftmost ($X_{\min} \leq 0$) visited sites up to time $t$. At each time step the existing particles in the system either diffuse (with diffusion constant $D$), die (with rate $a$) or split into two particles (with rate $b$). We focus on the regime $b \leq a$ where these two extreme values $X_{\max}$ and $X_{\min}$ are strongly correlated. We show that at large time $t$, the joint probability distribution function (PDF) of the two extreme points becomes stationary $P(X,Y,t \to \infty) \to p(X,Y)$. Our exact results for $p(X,Y)$ demonstrate that the correlation between $X_{\max}$ and $X_{\min}$ is nonzero, even in the stationary state. From this joint PDF, we compute exactly the stationary PDF $p(\zeta)$ of the (dimensionless) span $\zeta = {(X_{\max}  X_{\min})}/{\sqrt{D/b}}$, which is the distance between the rightmost and leftmost visited sites. This span distribution is characterized by a linear behavior ${p}(\zeta) \sim \frac{1}{2} \left(1 + \Delta \right) \zeta$ for small spans, with $\Delta = \left(\frac{a}{b} 1\right)$. In the critical case ($\Delta = 0$) this distribution has a nontrivial power law tail ${p}(\zeta) \sim 8 \pi \sqrt{3} /\zeta^3$ for large spans. On the other hand, in the subcritical case ($\Delta > 0$), we show that the span distribution decays exponentially as ${p}(\zeta) \sim (A^2/2) \zeta \exp \left( \sqrt{\Delta}~\zeta\right)$ for large spans, where $A$ is a nontrivial function of $\Delta$ which we compute exactly. We show that these asymptotic behaviors carry the signatures of the correlation between $X_{\max}$ and $X_{\min}$. Finally we verify our results via direct Monte Carlo simulations.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Spontaneously formed autofocusing caustics in a confined selfdefocusing medium
Michael Karpov ^{1} Thibault Congy ^{2} Yonatan Sivan ^{3} Victor Fleurov ^{1} Nicolas Pavloff ^{2} Shimshon BarAd ^{1}
Journal of Optical Networking, Optical Society of America, 2015, 2 (12), pp.1053. <10.1364/OPTICA.2.001053>
 1. Raymond and Beverly Sackler School of Physics and Astronomy
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. Ben Gurion University

Stable dilute supersolid of twodimensional dipolar bosons
ZhenKai Lu ^{1} Yun Li ^{2} D. S. Petrov ^{3} G. V. Shlyapnikov ^{4, 5, 3, 6}
Physical Review Letters, American Physical Society, 2015, 115, pp.075303
We consider twodimensional bosonic dipoles oriented perpendicularly to the plane. On top of the usual twobody contact and longrange dipolar interactions we add a contact threebody repulsion as expected, in particular, for dipoles in the bilayer geometry with tunneling. The threebody repulsion is crucial for stabilizing the system, and we show that our model allows for stable continuous space supersolid states in the dilute regime and calculate the zerotemperature phase diagram.
 1. Max Planck Institute für quantenoptik
 2. Swinburne University of Technology
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. Russian Quantum Center
 5. Wuhan Institute of Physics and Mathematics
 6. Van der Waals  Zeeman Institute

Statistical Curse of the Second Half Rank, Eulerian numbers and Stirling numbers
Stephane Ouvry ^{1}
Markov Processes and Related Fields, Polymath, 2015, 21, pp.779
I describe the occurence of Eulerian numbers and Stirling numbers of the second kind in the combinatorics of the Statistical Curse of the Second Half Rank problem.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Statistical physics methods provide the exact solution to a longstanding problem of genetics
Areejit Samal ^{1, 2, 3} Olivier C. Martin ^{4}
Physical Review Letters, American Physical Society, 2015, 114, pp.238101
Analytic and computational methods developed within statistical physics have found applications in numerous disciplines. In this letter, we use such methods to solve a longstanding problem in statistical genetics. The problem, posed by Haldane and Waddington [J.B.S. Haldane and C.H. Waddington, Genetics 16, 357374 (1931)], concerns socalled recombinant inbred lines (RILs) produced by repeated inbreeding. Haldane and Waddington derived the probabilities of RILs when considering 2 and 3 genes but the case of 4 or more genes has remained elusive. Our solution uses two probabilistic frameworks relatively unknown outside of physics: Glauber's formula and selfconsistent equations of the SchwingerDyson type. Surprisingly, this combination of statistical formalisms unveils the exact probabilities of RILs for any number of genes. Extensions of the framework may have applications in population genetics and beyond.
 1. The Abdus Salam International Centre for Theoretical Physics
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. MPIMIS  Max Planck Institute for Mathematics in the Sciences
 4. GQE  Génétique Quantitative et Evolution (Génétique Végétale)

Statistics of the longest interval in renewal processes
Claude Godreche ^{1} Satya N. Majumdar ^{2} Gregory Schehr ^{2}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2015, pp.P03014
We consider renewal processes where events, which can for instance be the zero crossings of a stochastic process, occur at random epochs of time. The intervals of time between events, $\tau_{1},\tau_{2},...$, are independent and identically distributed (i.i.d.) random variables with a common density $\rho(\tau)$. Fixing the total observation time to $t$ induces a global constraint on the sum of these random intervals, which accordingly become interdependent. Here we focus on the largest interval among such a sequence on the fixed time interval $(0,t)$. Depending on how the last interval is treated, we consider three different situations, indexed by $\alpha=$ I, II and III. We investigate the distribution of the longest interval $\ell^\alpha_{\max}(t)$ and the probability $Q^\alpha(t)$ that the last interval is the longest one. We show that if $\rho(\tau)$ decays faster than $1/\tau^2$ for large $\tau$, then the full statistics of $\ell^\alpha_{\max}(t)$ is given, in the large $t$ limit, by the standard theory of extreme value statistics for i.i.d. random variables, showing in particular that the global constraint on the intervals $\tau_i$ does not play any role at large times in this case. However, if $\rho(\tau)$ exhibits heavy tails, $\rho(\tau)\sim\tau^{1\theta}$ for large $\tau$, with index $0 <\theta<1$, we show that the fluctuations of $\ell^\alpha_{\max}(t)/t$ are governed, in the large $t$ limit, by a stationary universal distribution which depends on both $\theta$ and $\alpha$, which we compute exactly. On the other hand, $Q^{\alpha}(t)$ is generically different from its counterpart for i.i.d. variables (both for narrow or heavy tailed distributions $\rho(\tau)$). In particular, in the case $0<\theta<1$, the large $t$ behaviour of $Q^\alpha(t)$ gives rise to universal constants (depending also on both $\theta$ and $\alpha$) which we compute exactly.
 1. IPHT  Institut de Physique Théorique (ex SPhT)
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Statistics of twodimensional random walks, the « cyclic sieving phenomenon » and the Hofstadter model
Stefan Mashkevich ^{1, 2} Stéphane Ouvry ^{3} Alexios Polychronakos ^{4}
Journal of Physics A: Mathematical and Theoretical, IOP Publishing, 2015, 48, pp.405001
We focus on the algebraic area probability distribution of planar random walks on a square lattice with $m_1$, $m_2$, $l_1$ and $l_2$ steps right, left, up and down. We aim, in particular, at the algebraic area generating function $Z_{m_1,m_2,l_1,l_2}(Q)$ evaluated at $Q=e^{2\i\pi\over q}$, a root of unity, when both $m_1m_2$ and $l_1l_2$ are multiples of $q$. In the simple case of staircase walks, a geometrical interpretation of $Z_{m,0,l,0}(e^\frac{2i\pi}{q})$ in terms of the cyclic sieving phenomenon is illustrated. Then, an expression for $Z_{m_1,m_2,l_1,l_2}(1)$, which is relevant to the Stembridge's case, is proposed. Finally, the related problem of evaluating the nth moments of the Hofstadter Hamiltonian in the commensurate case is addressed.
 1. Schrodinger
 2. Bogolyubov Institute for Theoretical Physics
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 4. Physics Department

SU(3) and SU(4) singlet quantum Hall states at $\nu=2/3$
Fengcheng Wu ^{1} Inti Sodemann ^{1} Allan H. Macdonald ^{1} Thierry Jolicoeur ^{2}
Physical Review Letters, American Physical Society, 2015, 115, pp.166805
We report on an exact diagonalization study of fractional quantum Hall states at filling factor $\nu=2/3$ in a system with a fourfold degenerate $n$=0 Landau level and SU(4) symmetric Coulomb interactions. Our investigation reveals previously unidentified SU(3) and SU(4) singlet ground states which appear at flux quantum shift 2 when a spherical geometry is employed, and lie outside the established compositefermion or multicomponent Halperin state patterns. We evaluate the twoparticle correlation functions of these states, and discuss quantum phase transitions in graphene between singlet states with different number of components as magnetic field strength is increased.
 1. The University of Texas at Austin [Austin]
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Survival probability of a Brownian motion in a planar wedge of arbitrary angle
Marie Chupeau ^{1} Olivier Bénichou ^{1} Satya N. Majumdar ^{2}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2015, 91, pp.032106
We study the survival probability and the firstpassage time distribution for a Brownian motion in a planar wedge with infinite absorbing edges. We generalize existing results obtained for wedge angles of the form $\pi/n$ with $n$ a positive integer to arbitrary angles, which in particular cover the case of obtuse angles. We give explicit and simple expressions of the survival probability and the firstpassage time distribution in which the difference between an arbitrary angle and a submultiple of $\pi$ is contained in three additional terms. As an application, we obtain the short time development of the survival probability in a wedge of arbitrary angle.
 1. LPTMC  Laboratoire de Physique Théorique de la Matière Condensée
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Tensor Representation of Spin States
O. Giraud ^{1} D. Braun ^{2} D. Baguette ^{3} T. Bastin ^{3} J. Martin ^{3}
Physical Review Letters, American Physical Society, 2015, 114, pp.080401
We propose a generalization of the Bloch sphere representation for arbitrary spin states. It provides a compact and elegant representation of spin density matrices in terms of tensors that share the most important properties of Bloch vectors. Our representation, based on covariant matrices introduced by Weinberg in the context of quantum field theory, allows for a simple parametrization of coherent spin states, and a straightforward transformation of density matrices under local unitary and partial tracing operations. It enables us to provide a criterion for anticoherence, relevant in a broader context such as quantum polarization of light.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Tübingen Universität  Tübingen University
 3. Institut de Physique Nucléaire, Atomique et de Spectrométrie

The average number of distinct sites visited by a random walker on random graphs
Caterina De Bacco ^{1} Satya N. Majumdar ^{1} Peter Sollich ^{2}
Journal of Physics A: Mathematical and Theoretical, Institute of Physics: Hybrid Open Access, 2015, 48, pp.205004
We study the linear large $n$ behavior of the average number of distinct sites $S(n)$ visited by a random walker after $n$ steps on a large random graph. An expression for the graph topology dependent prefactor $B$ in $S(n) = Bn$ is proposed. We use generating function techniques to relate this prefactor to the graph adjacency matrix and then devise messagepassing equations to calculate its value. Numerical simulations are performed to evaluate the agreement between the message passing predictions and random walk simulations on random graphs. Scaling with system size and average graph connectivity are also analysed.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. King's College London

The contact theorem for charged fluids: from planar to curved geometries
Juan Pablo Mallarino ^{1} Gabriel Tellez ^{1} Emmanuel Trizac ^{2}
Molecular Physics, Taylor & Francis, 2015, 113, pp.2409
When a Coulombic fluid is confined between two parallel charged plates, an exact relation links the difference of ionic densities at contact with the plates, to the surface charges of these boundaries. It no longer applies when the boundaries are curved, and we work out how it generalizes when the fluid is confined between two concentric spheres (or cylinders), in two and in three space dimensions. The analysis is thus performed within the cell model picture. The generalized contact relation opens the possibility to derive new exact expressions, of particular interest in the regime of strong coulombic couplings. Some emphasis is put on cylindrical geometry, for which we discuss in depth the phenomenon of counterion evaporation/condensation, and obtain novel results. Good agreement is found with Monte Carlo simulation data.
 1. Departamento de Fisica
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

The critical catastrophe revisited
Clélia De Mulatier ^{1, 2} Eric Dumonteil ^{3} Alberto Rosso ^{2} Andrea Zoia ^{1}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2015, pp.P08021
The neutron population in a prototype model of nuclear reactor can be described in terms of a collection of particles confined in a box and undergoing three key random mechanisms: diffusion, reproduction due to fissions, and death due to absorption events. When the reactor is operated at the critical point, and fissions are exactly compensated by absorptions, the whole neutron population might in principle go to extinction because of the wild fluctuations induced by births and deaths. This phenomenon, which has been named critical catastrophe, is nonetheless never observed in practice: feedback mechanisms acting on the total population, such as human intervention, have a stabilizing effect. In this work, we revisit the critical catastrophe by investigating the spatial behaviour of the fluctuations in a confined geometry. When the system is free to evolve, the neutrons may display a wild patchiness (clustering). On the contrary, imposing a population control on the total population acts also against the local fluctuations, and may thus inhibit the spatial clustering. The effectiveness of population control in quenching spatial fluctuations will be shown to depend on the competition between the mixing time of the neutrons (i.e., the average time taken for a particle to explore the finite viable space) and the extinction time.
 1. DM2S  Département de Modélisation des Systèmes et Structures
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 3. SERMA  Service des Réacteurs et de Mathématiques Appliquées

The crossing probability for directed polymers in random media
Andrea De Luca ^{1} Pierre Le Doussal ^{2}
Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, American Physical Society, 2015, 92, pp.040102
We study the probability that two directed polymers in the same random potential do not intersect. We use the replica method to map the problem onto the attractive LiebLiniger model with generalized statistics between particles. We obtain analytical expressions for the first few moments of this probability, and compare them to a numerical simulation of a discrete model at hightemperature. From these observations, several large time properties of the noncrossing probabilities are conjectured. Extensions of our formalism to more general observables are discussed.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. LPTENS  Laboratoire de Physique Théorique de l'ENS

The edgedisjoint path problem on random graphs by messagepassing
Fabrizio Altarelli ^{1, 2} Alfredo Braunstein ^{3, 1, 2} Luca Dall'Asta ^{1, 2} Caterina De Bacco ^{4} Silvio Franz ^{4}
PLoS ONE, Public Library of Science, 2015, 10, pp.0145222
We present a messagepassing algorithm to solve the edge disjoint path problem (EDP) on graphs incorporating under a unique framework both traffic optimization and path length minimization. The minsum equations for this problem present an exponential computational cost in the number of paths. To overcome this obstacle we propose an efficient implementation by mapping the equations onto a weighted combinatorial matching problem over an auxiliary graph. We perform extensive numerical simulations on random graphs of various types to test the performance both in terms of path length minimization and maximization of the number of accommodated paths. In addition, we test the performance on benchmark instances on various graphs by comparison with stateoftheart algorithms and results found in the literature. Our messagepassing algorithm always outperforms the others in terms of the number of accommodated paths when considering non trivial instances (otherwise it gives the same trivial results). Remarkably, the largest improvement in performance with respect to the other methods employed is found in the case of benchmarks with meshes, where the validity hypothesis behind messagepassing is expected to worsen. In these cases, even though the exact messagepassing equations do not converge, by introducing a reinforcement parameter to force convergence towards a sub optimal solution, we were able to always outperform the other algorithms with a peak of 27% performance improvement in terms of accommodated paths. On random graphs, we numerically observe two separated regimes: one in which all paths can be accommodated and one in which this is not possible. We also investigate the behaviour of both the number of paths to be accommodated and their minimum total length.
 1. DISAT  Department of Applied Science and Technology
 2. Collegio Carlo Alberto
 3. HuGeF  Human Genetics Foundation
 4. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Threebody recombination in heteronuclear mixtures at finite temperature
D. S. Petrov ^{1} F. Werner ^{2}
Physical Review A, American Physical Society, 2015, 92, pp.022704
Within the universal zerorange theory, we compute the threebody recombination rate to deep molecular states for two identical bosons resonantly interacting with each other and with a third atom of another species, in the absence of weakly bound dimers. The results allow for a quantitative understanding of loss resonances at finite temperature and, combined with experimental data, can be used for testing the Efimov universality and extracting the corresponding threebody parameters in a given system. Curiously, we find that the loss rate can be dramatically enhanced by the resonant heavyheavy interaction, even for large mass ratios where this interaction is practically irrelevant for the Efimov scaling factor. This effect is important for analysing the recent loss measurements in the CsLi mixture.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. LKB (Jussieu)  Laboratoire Kastler Brossel

Towards an $H$theorem for granular gases
M. I. García De Soria ^{1} P. Maynar ^{1} S. Mischler ^{2} C. Mouhot ^{3} T. Rey ^{4} E. Trizac ^{5}
Journal of Statistical Mechanics: Theory and Experiment, IOP Publishing, 2015, pp.P11009
The $H$theorem, originally derived at the level of Boltzmann nonlinear kinetic equation for a dilute gas undergoing elastic collisions, strongly constrains the velocity distribution of the gas to evolve irreversibly towards equilibrium. As such, the theorem could not be generalized to account for dissipative systems: the conservative nature of collisions is an essential ingredient in the standard derivation. For a dissipative gas of grains, we construct here a simple functional $\mathcal H$ related to the original $H$, that can be qualified as a Lyapunov functional. It is positive, and results backed by three independent simulation approaches (a deterministic spectral method, the stochastic Direct Simulation Monte Carlo technique, and Molecular Dynamics) indicate that it is also nonincreasing. Both driven and unforced cases are investigated.
 1. Fisica Teorica, Universidad de Sevilla
 2. CEREMADE  CEntre de REcherches en MAthématiques de la DEcision
 3. DPMMS/CMS
 4. LPP  Laboratoire Paul Painlevé
 5. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Towards an Htheorem for granular gases
Maria Isabel Garcia de Soria ^{1} Pablo Maynar ^{1} S Mischler ^{2} Clément Mouhot ^{3} Thomas Rey ^{4, 5} Emmanuel Trizac ^{6}
Journal of Statistical Mechanics: Theory and Experiment, IOP Science, 2015, 2015, <http://iopscience.iop.org/article/10.1088/17425468/2015/11/P11009>. <10.1088/17425468/2015/11/P11009>
The Htheorem, originally derived at the level of Boltzmann nonlinear kinetic equation for a dilute gas undergoing elastic collisions, strongly constrains the velocity distribution of the gas to evolve irreversibly towards equilibrium. As such, the theorem could not be generalized to account for dissipative systems: the conservative nature of collisions is an essential ingredient in the standard derivation. For a dissipative gas of grains, we construct here a simple functional H related to the original H, that can be qualified as a Lyapunov functional. It is positive, and results backed by three independent simulation approaches (a deterministic spectral method, the stochastic Direct Simulation Monte Carlo technique, and Molecular Dynamics) indicate that it is also nonincreasing. Both driven and unforced cases are investigated.
 1. Fisica Teorica, Universidad de Sevilla
 2. CEREMADE  CEntre de REcherches en MAthématiques de la DEcision
 3. DPMMS/CMS
 4. Laboratoire de Mathématiques Paul Painlevé
 5. RAPSODI  Reliable numerical approximations of dissipative systems
 6. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Ultracold atoms: Boltzmann avenged
David GuéryOdelin ^{1} Emmanuel Trizac ^{2}
Nature Physics, Nature Publishing Group, 2015, 11 (12), pp.988. <10.1038/nphys3522>
 1. Atomes Froids (LCAR)
 2. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Unidirectional light emission from lowindex polymer microlasers
M. SchermerS. Bittner ^{1} G. SinghC. Ulysse ^{2} M. Lebental ^{1, 3} J. Wiersig
Applied Physics Letters, American Institute of Physics, 2015, 106 (10), <10.1063/1.4914498>
 1. LPQM  Laboratoire de Photonique Quantique et Moléculaire
 2. LPN  Laboratoire de photonique et de nanostructures
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Universal groundstate properties of free fermions in a ddimensional trap
David S. Dean ^{1} Pierre Le Doussal ^{2} Satya N. Majumdar ^{3} Grégory Schehr ^{3}
EPL, European Physical Society/EDP Sciences/Società Italiana di Fisica/IOP Publishing, 2015, 112 (6), pp.60001 (16). <www.epljournal.org>. <10.1209/02955075/112/60001>
The groundstate properties of N spinless free fermions in a ddimensional confining potential are studied. We find that any npoint correlation function has a simple determinantal structure that allows us to compute several properties exactly for large N. We show that the average density has a finite support with an edge, and near this edge the density exhibits a universal (valid for a wide class of potentials) scaling behavior for large N. The associated edge scaling function is computed exactly and generalizes to any d the edge electron gas result of Kohn and Mattsson in d = 3 (Kohn W. and Mattsson A. E., Phys. Rev. Lett., 81 (1998) 3487). In addition, we calculate the kernel (that characterizes any npoint correlation function) for large N and show that, when appropriately scaled, it depends only on dimension d, but has otherwise universal scaling forms, at the edges. The edge kernel, for higher d, generalizes the Airy kernel in one dimension, well known from the random matrix theory.
 1. LOMA  Laboratoire Ondes et Matière d'Aquitaine
 2. LPTENS  Laboratoire de Physique Théorique de l'ENS
 3. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques

Universal Spectrum of Normal Modes in LowTemperature Glasses: an Exact Solution
Silvio Franz ^{1} Giorgio Parisi ^{2} Pierfrancesco Urbani ^{3} Francesco Zamponi ^{4}
Proceeding of the national academy of sciences, National Academy of Sciences, 2015, 112, pp.14539
We report an analytical study of the vibrational spectrum of the simplest model of jamming, the soft perceptron. We identify two distinct classes of soft modes. The first kind of modes are related to isostaticity and appear only in the close vicinity of the jamming transition. The second kind of modes instead are present everywhere in the glass phase and are related to the hierarchical structure of the potential energy landscape. Our results highlight the universality of the spectrum of normal modes in disordered systems, and open the way towards a detailed analytical understanding of the vibrational spectrum of lowtemperature glasses.
 1. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 2. Dipartimento di Fisica and INFM
 3. IPHT  Institut de Physique Théorique  UMR CNRS 3681
 4. ETH Zurich

Archive ouverte HAL – The JEMEUSO mission: An introduction
J. AdamsS. Ahmad ^{1} J.N. Albert ^{2} D. Allard ^{3} L. AnchordoquiV. AndreevA. Anzalone ^{4} Y. AraiK. Asano ^{5} M. Ave PernasP. BaragattiP. Barrillon ^{2} T. BatschJ. BayerR. BechiniT. BelenguerR. BellottiK. BelovA. BerlindM. BertainaP. BiermannS. BiktemerovaC. Blaksley ^{3} N. Blanc ^{6} J. BłȩckiS. BlinBondil ^{1} J. BlümerP. BobikM. BogomilovM. BonamenteM. BriggsS. BrizA. BrunoF. Cafagna ^{7} D. CampanaJN. Capdevielle ^{3} R. CarusoM. CasolinoC. CassardoG. CastelliniC. Catalano ^{8} O. CatalanoA. Cellino ^{9} M. ChikawaM. Christl ^{10} D. ClineV. Connaughton ^{11} L. ContiG. CorderoH. CrawfordR. CremoniniS. CsornaS. DagoretCampagne ^{2} A. de CastroC. de DonatoC. de la Taille ^{1} C. de SantisL. del PeralA. Dell’oroN. de Simone ^{12} M. Di MartinoG. DistratisF. Dulucq ^{1} M. DupieuxA. Ebersoldt ^{13} T. EbisuzakiR. EngelS. Falk ^{14} K. FangF. FenuI. FernándezGómezS. FerrareseD. FincoM. FlaminiC. FornaroA. FranceschiJ. FujimotoM. Fukushima ^{15} P. GaleottiG. GaripovJ. GearyG. Gelmini ^{16} G. Giraudo ^{17} M. Gonchar ^{18} C. González AlvaradoP. Gorodetzky ^{3} F. GuarinoA. GuzmánY. HachisuB. HarlovA. HaungsJ. Hernández CarreteroK. HigashideD. IkedaH. IkedaN. InoueS. Inoue ^{19} A. InsoliaF. IsgròY. Itow ^{20} E. JovenE. JuddA. Jung ^{21} F. KajinoT. KajinoI. KanekoY. KaradzhovJ. KarczmarczykM. KarusK. KatahiraK. KawaiY. KawasakiB. KeilhauerB. KhrenovJeongSook KimSoonWook KimSugWhan KimM. KleifgesP. KlimovD. KolevI. Kreykenbohm ^{22} K. Kudela ^{23} Y. Kurihara ^{24} A. KusenkoE. KuznetsovM. LacombeC. Lachaud ^{3} J. Lee ^{25} J. Licandro ^{26} H. LimF. LopezM. MaccaroneK. MannheimD. MaravillaL. MarcelliA. MariniO. MartinezG. MasciantonioK. Mase ^{27} R. MatevG. MedinaTancoT. MernikH. Miyamoto ^{2} Y. Miyazaki ^{28} Y. MizumotoG. ModestinoA. MonacoD. MonnierRagaigne ^{2} J. Morales de los RíosC. Moretto ^{2} V. MorozenkoB. Mot ^{8} T. Murakami ^{29} M. NaganoM. Nagata ^{30} S. NagatakiT. NakamuraT. NapolitanoD. NaumovR. NavaA. Neronov ^{31} K. NomotoT. NonakaT. OgawaS. OgioH. OhmoriA. Olinto ^{3} P. OrleańskiG. OsteriaM. PanasyukE. Parizot ^{3} I. ParkH. Park ^{32} B. PastircakT. Patzak ^{3} T. Paul ^{33} C. PennypackerS. Perez CanoT. PeterP. PicozzaT. PierogL. PiotrowskiS. PirainoZ. PlebaniakA. PolliniP. Prat ^{3} G. Prévot ^{3} H. PrietoM. PutisP. ReardonM. Reyes ^{34} M. RicciI. RodríguezM. FríasF. RongaM. Roth ^{35} H. Rothkaehl ^{36} G. Roudil ^{37} I. RusinovM. RybczyńskiM. SabauG. Sáez CanoH. Sagawa ^{38} A. SaitoN. SakakiM. SakataH. SalazarS. Sanchez ^{39} A. SantangeloL. Santiago CrúzM. Sanz PalominoO. SaprykinF. Sarazin ^{40} H. Sato ^{41} M. SatoT. SchanzH. SchielerV. Scotti ^{42} A. SegretoS. Selmane ^{3} D. Semikoz ^{3} M. SerraS. SharakinT. ShibataH. Shimizu ^{43} K. ShinozakiT. ShirahamaG. SiemieniecOziȩbłoH. Silva LópezJ. SleddK. SłomińskaA. SobeyT. Sugiyama ^{44} D. SupanitskyM. Suzuki ^{45} B. SzabelskaJ. SzabelskiF. TajimaN. TajimaT. TajimaY. TakahashiH. TakamiM. TakedaY. TakizawaC. TenzerO. Tibolla ^{46} L. TkachevH. TokunoT. TomidaN. ToneS. Toscano ^{47} F. Trillaud ^{48} R. TsenovY. TsunesadaK. TsunoT. TymienieckaY. UchihoriM. Unger ^{49} O. Vaduvescu ^{50} J. ValdésGaliciaP. VallaniaL. ValoreG. VankovaC. VigoritoL. VillaseñorP. von Ballmoos ^{8} S. WadaJ. WatanabeS. WatanabeJ. WattsM. Weber ^{51} T. WeilerT. WibigL. WienckeM. WilleJ. Wilms ^{52} Z. WłodarczykT. Yamamoto ^{53} Y. YamamotoJ. Yang ^{54} H. YanoI. YashinD. YonetokuK. YoshidaS. YoshidaR. YoungM. Yu. ZotovA. Zuccaro Marchi
J. Adams, S. Ahmad, J.N. Albert, D. Allard, L. Anchordoqui, et al.. The JEMEUSO mission: An introduction. Experimental Astronomy, Springer Link, 2015, 40 (1), pp.317. ⟨10.1007/s106860159482x⟩. ⟨hal02478688⟩
 1. OMEGA  Organisation de MicroÉlectronique Générale Avancée
 2. LAL  Laboratoire de l'Accélérateur Linéaire
 3. APC (UMR_7164)  AstroParticule et Cosmologie
 4. LNS  Laboratori Nazionali del Sud
 5. Division of Biology, Kansas State University
 6. CTC
 7. University of Bari and INFN section of Bari
 8. IRAP  Institut de recherche en astrophysique et planétologie
 9. OATo  INAF  Osservatorio Astrofisico di Torino
 10. ETH Zürich  Eidgenössische Technische Hochschule  Swiss Federal Institute of Technology in Zürich [Zürich]
 11. USRA  Universities Space Research Association
 12. Regione Emilia Romagna
 13. IPE  Institute for Data Processing and Electronics
 14. Institute for Ecology
 15. Tokushima research center
 16. Department of Physics and Astronomy [UCLA, Los Angeles]
 17. INFN, Sezione di Torino  Istituto Nazionale di Fisica Nucleare, Sezione di Torino
 18. Institute of Applied Biotechnology and Basic Sciences
 19. Hiroshima University  Department of Mechanical System
 20. Nagoya University
 21. Department of Pathology
 22. FAU  FriedrichAlexander Universität ErlangenNürnberg
 23. Institute of Experimental Physics of Kosice
 24. High energy accelerator research organization  KEK
 25. iMagX/MIRO
 26. IAC  Instituto de Astrofisica de Canarias
 27. OUJ  The Open University of Japan [Chiba]
 28. Tohoku University [Sendai]
 29. Department of Earth and Planetary Science [Tokyo]
 30. Department of Electrical Engineering and Computer Sciences
 31. ISDC  INTEGRAL Science Data Center
 32. Service de dermatologie et vénéréologie (CHUV Lausanne)
 33. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 34. ISTB  Institute for Surgical Technology and Biomechanics [Bern]
 35. Centre IRMf de Marseille
 36. CBK  Space Research Centre of Polish Academy of Sciences
 37. CESR  Centre d'étude spatiale des rayonnements
 38. Center for Mathematics and Physics
 39. CR2P  Centre de recherche sur la Paléobiodiversité et les Paléoenvironnements
 40. Colorado School of Mines
 41. Department of Physics  Department of Physics
 42. Department of RadiationOncology
 43. KEK  High Energy Accelerator Research Organization
 44. Graduate School of Materials Science
 45. OOB  Observatoire océanologique de Banyuls
 46. MPIK  MaxPlanckInstitut für Kernphysik
 47. VUB  Vrije Universiteit Brussel
 48. G2ELab  Laboratoire de Génie Electrique de Grenoble
 49. Institute of Sensor and Actuator Systems
 50. IMCCE  Institut de Mécanique Céleste et de Calcul des Ephémérides
 51. LIST  Luxembourg Institute of Science and Technology
 52. Dr. KarlRemeisSternwarte
 53. Kyoto University [Kyoto]
 54. UCONN  University of Connecticut

Archive ouverte HAL – Improved limit to the diffuse flux of ultrahigh energy neutrinos from the Pierre Auger Observatory
A. AabP. AbreuM. AgliettaE. j. AhnI. Al Samarai ^{1} I. f. m. AlbuquerqueI. AllekotteP. AllisonA. AlmelaJ. Alvarez CastilloJ. AlvarezMuñizR. Alves BatistaM. AmbrosioA. AminaeiL. AnchordoquiS. AndringaC. AramoV. m. ArandaF. ArquerosN. ArseneH. AsoreyP. AssisJ. Aublin ^{2} M. AveM. Avenier ^{3} G. AvilaN. AwalA. m. BadescuK. b. BarberJ. BäumlC. BausJ. j. BeattyK. h. BeckerJ. a. BellidoC. Bérat ^{3} M. e. BertainaX. BertouP. l. BiermannP. Billoir ^{2} S. g. BlaessA. BlancoM. Blanco ^{2} C. BleveH. BlümerM. BoháčováD. BoncioliC. BonifaziN. BorodaiJ. BrackI. BrancusA. BridgemanP. BrogueiraW. c. BrownP. BuchholzA. BuenoS. Buitink ^{4} M. BuscemiK. s. CaballeroMoraB. CaccianigaL. Caccianiga ^{2} M. CandussoL. CarameteR. CarusoA. CastellinaG. CataldiL. CazonR. CesterA. g. ChavezA. Chiavassa ^{5} J. a. ChinellatoJ. ChudobaM. CilmoR. w. ClayG. CoccioloR. ColalilloA. ColemanL. CollicaM. r. ColucciaR. ConceiçãoF. ContrerasM. j. CooperA. Cordier ^{6} S. CoutuC. e. CovaultJ. CroninRichard Dallier ^{7} B. DanielS. Dasso ^{8} K. DaumillerB. r. DawsonR. m. de AlmeidaS. j. de JongG. de MauroJ. r. t. de Mello NetoI. de MitriJ. de Oliveira ^{9} V. de SouzaL. del PeralO. Deligny ^{1} H. DembinskiN. DhitalC. Di GiulioA. Di MatteoJ. c. DiazM. l. Díaz CastroF. DiogoC. DobrigkeitW. DoctersJ. c. D’olivoA. DorofeevQ. Dorosti HasankiadehM. t. DovaJ. EbrR. EngelM. ErdmannM. ErfaniC. o. EscobarJ. EspadanalA. EtchegoyenH. Falcke ^{10} K. FangG. FarrarA. c. FauthN. FazziniA. p. FergusonM. FernandesB. FickJ. m. FigueiraA. FilevichA. FilipčičB. d. FoxO. FratuM. m. FreireB. FuchsT. Fujii ^{11} B. GarcíaD. GarciaPintoF. GatéH. GemmekeA. GherghelLascuP. l. Ghia ^{2} U. GiaccariM. GiammarchiM. GillerD. GłasC. GlaserH. GlassG. GolupM. Gomez Berisso ^{12} P. f. Gómez VitaleN. GonzálezB. GookinJ. GordonA. GorgiP. GorhamP. GouffonN. GriffithA. f. GrilloT. d. GrubbY. GuardincerriF. GuarinoG. p. GuedesM. r. HampelP. HansenD. HarariT. a. HarrisonS. HartmannJ. l. HartonA. HaungsT. HebbekerD. HeckP. Heimann ^{13} A. e. HerveG. c. HillC. HojvatN. HollonE. HoltP. HomolaJ. r. Hörandel ^{4} P. HorvathM. HrabovskýD. Huber ^{14} T. Huege ^{15} A. InsoliaP. g. IsarI. JandtS. JansenC. JarneJ. a. JohnsenM. JosebachuiliA. KääpäO. KambeitzK. h. KampertP. KasperI. KatkovB. Kégl ^{6} B. KeilhauerA. Keivani ^{16} E. KempR. m. KieckhaferH. o. KlagesM. KleifgesJ. KleinfellerR. KrauseN. KrohmO. KrömerD. KuempelN. KunkaD. LahurdL. Latronico ^{17} R. LauerM. LauscherPascal LautridouS. Le Coz ^{3} D. Lebrun ^{3} P. LebrunM. a. Leigui de OliveiraA. LetessierSelvon ^{2} I. LhenryYvon ^{1} K. LinkL. LopesR. LópezA. López CasadoK. Louedec ^{3} L. LuA. LuceroM. MalacariS. Maldera ^{17} M. Mallamaci ^{18} J. Maller ^{19} D. MandatP. MantschA. g. MariazziV. Marin ^{19} I. c. MarişG. MarsellaD. MartelloLilian Martin ^{7} H. Martinez ^{20} O. Martínez BravoD. Martraire ^{1} J. j. Masías MezaH. j. MathesS. MathysJ. a. j. MatthewsG. Matthiae ^{19} D. MaurelD. MaurizioE. MayotteP. o. MazurC. MedinaG. MedinaTancoR. MeissnerV. b. b. MelloD. MeloA. MenshikovS. MessinaR. MeyhandanM. i. MichelettiL. MiddendorfI. a. MinayaL. MiramontiB. Mitrica ^{21} L. MolinaBuenoS. MollerachF. Montanet ^{3} C. MorelloM. MostafáC. a. MouraM. a. MullerG. MüllerS. Muller ^{22} R. MussaG. Navarra ^{23} J. l. NavarroS. NavasP. NecesalL. NellenA. Nelles ^{4} J. NeuserP. h. NguyenM. NiculescuOglinzanuM. NiechciolL. NiemietzT. NiggemannD. NitzD. NosekV. NovotnyL. NožkaL. OchiloF. OikonomouA. OlintoN. PachecoD. Pakk SelmiDeiM. PalatkaJ. PallottaP. PapenbreerG. ParenteA. ParraT. Paul ^{24} M. PechJ. PȩkalaR. PelayoI. m. PepeL. PerroneE. PetermannC. PetersS. PetreraY. PetrovJ. PhuntsokR. PiegaiaT. Pierog ^{19} P. PieroniM. PimentaV. PirronelloM. PlatinoM. PlumA. PorcelliC. PorowskiR. r. PradoP. PriviteraM. ProuzaV. PurrelloE. j. QuelS. QuerchfeldS. QuinnJ. RautenbergO. Ravel ^{19} D. RavignaniBenoît RevenuJ. RidkyS. RiggiM. RisseP. RistoriV. RiziW. Rodrigues de CarvalhoG. Rodriguez FernandezJ. Rodriguez RojoM. d. RodríguezFríasD. RogozinJ. RosadoM. Roth ^{25} E. RouletA. c. RoveroS. j. SaffiA. SaftoiuF. Salamida ^{1} H. SalazarA. Saleh ^{26} F. Salesa GreusG. SalinaF. Sanchez ^{27} P. SanchezLucasE. m. SantosF. Sarazin ^{28} B. SarkarR. SarmentoR. SatoC. ScarsoM. SchauerV. ScheriniH. SchielerP. SchifferD. SchmidtO. Scholten ^{29} H. SchoorlemmerP. SchovánekF. g. SchröderA. SchulzJ. SchulzJ. SchumacherS. j. SciuttoA. Segreto ^{30} M. Settimo ^{2} A. ShadkamR. c. ShellardI. SidelnikG. SiglO. Sima ^{31} A. ŚmiałkowskiR. ŠmídaG. r. SnowP. SommersJ. SorokinR. SquartiniY. n. SrivastavaD. StancaS. StaničJ. StapletonJ. StasielakM. StephanA. Stutz ^{3} F. SuarezT. Suomijarvi ^{1} A. d. SupanitskyM. s. SutherlandJ. SwainZ. SzadkowskiO. a. TabordaA. TapiaA. TepeV. m. TheodoroJ. TiffenbergC. TimmermansC. j. Todero PeixotoG. TomaL. TomankovaB. ToméA. TonachiniG. Torralba ElipeD. Torres Machado ^{19} P. TravnicekR. UlrichM. UngerM. UrbanJ. f. Valdés GaliciaI. ValiñoL. ValoreG. van AarP. van Bodegom ^{32} A. m. van den BergS. van Velzen ^{10} A. van VlietE. VarelaB. Vargas CárdenasG. Varner ^{33} R. VasquezJ. r. VázquezR. a. VázquezD. Veberič ^{34} V. VerziJ. VichaM. VidelaL. VillaseñorB. VlcekS. Vorobiov ^{34} H. WahlbergO. WainbergD. Walz ^{35} A. a. WatsonM. WeberK. WeidenhauptA. WeindlF. Werner ^{36} A. WidomL. WienckeH. WilczyńskiT. WinchenD. WittkowskiB. WundheilerS. WykesL. Yang ^{37} T. YapiciA. YushkovE. ZasD. ZavrtanikM. ZavrtanikA. ZepedaY. ZhuB. Zimmermann ^{38} M. ZiolkowskiF. Zuccarello ^{39}
A. Aab, P. Abreu, M. Aglietta, E. j. Ahn, I. Al Samarai, et al.. Improved limit to the diffuse flux of ultrahigh energy neutrinos from the Pierre Auger Observatory. Physical Review D, American Physical Society, 2015, 91 (9), ⟨10.1103/PhysRevD.91.092008⟩. ⟨hal02467626⟩
 1. IPNO  Institut de Physique Nucléaire d'Orsay
 2. LPNHE  Laboratoire de Physique Nucléaire et de Hautes Énergies
 3. LPSC  Laboratoire de Physique Subatomique et de Cosmologie
 4. Department of Astrophysics [Nijmegen]
 5. LAGRANGE  Joseph Louis LAGRANGE
 6. LAL  Laboratoire de l'Accélérateur Linéaire
 7. USN  Unité Scientifique de la Station de Nançay
 8. UBA  Universidad de Buenos Aires [Buenos Aires]
 9. INSP  Institut des Nanosciences de Paris
 10. ASTRON  Netherlands Institute for Radio Astronomy
 11. LIMMS  Laboratory for Integrated Micro Mechatronics Systems
 12. CABCNEA  Division Bajas Temperaturas
 13. LBNL  Lawrence Berkeley National Laboratory [Berkeley]
 14. SIfA  Sydney Institute for Astronomy
 15. KIT  Karlsruher Institut für Technologie
 16. Penn State  Pennsylvania State University
 17. INFN, Sezione di Torino  Istituto Nazionale di Fisica Nucleare, Sezione di Torino
 18. INFN, Sezione di Bologna  Istituto Nazionale di Fisica Nucleare, Sezione di Bologna
 19. SUBATECH  Laboratoire SUBATECH Nantes
 20. ASSTV  Association des services de santé au travail de la Vienne
 21. National Institute of Physics and Nuclear Engineering
 22. ICT  Immunologie et chimie thérapeutiques
 23. Dipartimento di Fı'sica Generale dell'Università
 24. LPTMS  Laboratoire de Physique Théorique et Modèles Statistiques
 25. Division Applied Science
 26. NRIAG  National Research Institute of Astronomy and Geophysics [Helwan]
 27. POMA  Propriétés Optiques des Matériaux et Applications
 28. Colorado School of Mines
 29. Radboud university [Nijmegen]
 30. IASFPa  Istituto di Astrofisica Spaziale e Fisica cosmica  Palermo
 31. Department of Physics
 32. VU  Vrije Universiteit Amsterdam [Amsterdam]
 33. UHM  University of Hawai‘i [Mānoa]
 34. LAPUNG  Laboratory for astroparticle physics
 35. SLAC  Stanford Linear Accelerator Center
 36. LKB (Jussieu)  Laboratoire Kastler Brossel
 37. Department of Materials Science and Engineering [Korea]
 38. A. A. Noyes Laboratory of Chemical Physics
 39. LESIA  Laboratoire d'études spatiales et d'instrumentation en astrophysique