2003

Polynomial iterative algorithms for coloring and analyzing random graphs – Archive ouverte HAL

A. BraunsteinR. MuletA. Pagnani 1 M. WeigtR. Zecchina A. Braunstein, R. Mulet, A. Pagnani, M. Weigt, R. Zecchina. Polynomial iterative algorithms for coloring and analyzing random graphs. Physical Review E, 2003, 68, ⟨10.1103/PhysRevE.68.036702⟩. ⟨insu-03726414⟩ We study the graph coloring problem over random graphs of finite average connectivity c. Given a number q of available colors, …

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XY frustrated systems: Continuous exponents in discontinuous phase transitions

Mathieu Tissier 1, Bertrand Delamotte 2, Dominique Mouhanna 2 Physical Review B 67 (2003) 134422 XY frustrated magnets exhibit an unsual critical behavior: they display scaling laws accompanied by nonuniversal critical exponents and a negative anomalous dimension. This suggests that they undergo weak first order phase transitions. We show that all perturbative approaches that have been used to investigate XY frustrated …

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Topological correlations in trivial knots: new arguments in support of the crumpled polymer globule

Oleg A. Vasilyev 1, Sergei K. Nechaev 1, 2 Theoretical and Mathematical Physics 134 (2003) 142-159 We prove the fractal crumpled structure of collapsed unknotted polymer ring. In this state the polymer chain forms a system of densely packed folds, mutually separated in all scales. The proof is based on the numerical and analytical investigation of topological correlations in randomly generated dense …

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The LLL Anyon equation of state in the antiscreening regime

Stefan Mashkevich 1, Stéphane Ouvry 2 Physics Letters A 310 (2003) 85-94 The thermodynamics of the anyon model projected on the lowest Landau level (LLL) of an external magnetic field is addressed in the anti-screening regime, where the flux tubes carried by the anyons are parallel to the magnetic field. It is claimed that the LLL-anyon equation of state, …

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The Impact of Discoveries of Ferroelectricity and Charge Disproportionation in Organic Conductors

Serguei Brazovskii 1 Synthetic Metals 133-134 (2003) 301-303 Discoveries of the Ferroelectric anomaly (Nad, Monceau, et al) and of the related charge disproportionation (Brown et al) call for a revaluation of the phase diagram of the (TMTTF)2X compounds and return the attention to the interplay of electronic and structural properties. We shall describe a concept of the …

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The General O(n) Quartic Matrix Model and its application to Counting Tangles and Links

Paul Zinn-Justin 1 Communications in Mathematical Physics 238 (2003) 287-304 The counting of alternating tangles in terms of their crossing number, number of external legs and connected components is presented here in a unified framework using quantum field-theoretic methods applied to a matrix model of colored links. The overcounting related to topological equivalence of diagrams is removed …

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