Next seminar : Séminaire du LPTMS: Valentina Ros

Tuesday, October 23 2018 at 11:00:00

Arrangement of local minima and phase transitions in the energy landscape of simple glassy models

Valentina Ros (IPhT, CEA-Saclay)

Understanding the statistical properties of the stationary points of high-dimensional, random energy landscapes is a central problem in the physics of glassy systems, as well as in interdisciplinary applications to computer science, ecology and biology. In this talk, I will discuss a framework to perform the computation of the quenched complexity of stationary points, making use of a replicated version of the Kac-Rice formula. I will discuss its application to simple models (the spiked tensor model and its generalizations) which capture the competition between a deterministic signal and stochastic noise, and correspond to a spherical p-spin Hamiltonian endowed with ferromagnetic multi-body interaction terms. I will describe the phase transitions that occur in the structure of the landscape when changing the signal-to-noise ratio, and highlight the implications for the evolution of local dynamics within the landscape. Reference:
  • Valentina Ros, Gerard Ben Arous, Giulio Biroli and Chiara Cammarota, Complex energy landscapes in spiked-tensor and simple glassy models: ruggedness, arrangements of local minima and phase transitions, preprint cond-mat arXiv:1804.02686

Last Highlight : C’est chaud une ville la nuit

Il tend à faire plus chaud en centre-ville qu’en banlieue, mais certains centres chauffent davantage que d’autres. Une équipe de recherche internationale vient d’établir que la disposition des immeubles conditionne la température nocturne des villes – une découverte clé pour l’urbanisme de demain.

Voir la suite de l'article sur  CNRS - le journal

Ref. : J. M. Sobstyl, T. Emig, M. J. Abdolhosseini Qomi, F.-J. Ulm et R. J.-M. Pellenq, Role of City Texture in Urban Heat Islands at Nighttime, Phys. Rev. Lett. 120, 108701 (2018)

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