Statut  Confirmé 
Série  FORUMENS 
Domaines  condmat.statmech 
Date  Mercredi 22 Mai 2024 
Heure  12:45 
Institut  LPENS 
Salle  3 rue d'Ulm 
Nom de l'orateur  Michel 
Prenom de l'orateur  Manon 
Addresse email de l'orateur  
Institution de l'orateur  Universite ClermontAuvergne 
Titre  Symmetries, conservation laws and (non)reversibility 
Résumé  At the mesoscopic scale, the equilibrium dynamics of a system are typically modeled as reversible and Markovian, preserving the Boltzmann measure. The macroscopic properties of the system are fully described by ensemble averages following this measure and they can be estimated by time expectations along a carefully chosen Markov processes. Designing efficient Markovian dynamics leaving invariant some target distribution comes down to finding how to design a global structure of probability flows from local information. In the general case, this is made possible by breaking the timereversal symmetry of the usual detailedbalance dynamics. This presentation will discuss a collection of works pertaining to nonreversible Markov processes and explore the interplay between the invariance of the stationary probability distribution and certain key symmetries. These key symmetries now serve as the basis for necessary probability flow conservation, having replaced the timereversal symmetry that is now broken. Notably, these investigations span both equilibrium and non equilibrium systems. It is indeed possible to define the universality classes of some active particle systems based on the satisfaction or not of some skewdetailed symmetry. Interestingly, this reflection extends to reversible cluster algorithms as well, as it revolves around the same core concept of phase space extension. In such algorithms, the flip involutive symmetry plays a crucial role in ensuring correctness, and can be mapped to the conservation of random currents in the flow or loop graphical representation. 
Numéro de preprint arXiv  
Commentaires  
Fichiers attachés 
Pour obtenir l' affiche de ce séminaire : [ Postscript  PDF ]

[ English version ] 