Exposé

Grandes déviations pour les trajectoires quantiques : un regard sur l'instrument Keep–Switch

Lundi, 3 novembre 2025 - 11:00 - 12:00

Résumé : Cet exposé porte sur les grandes déviations des trajectoires quantiques issues de processus de mesures répétées. Ces trajectoires sont décrites par des chaînes de Markov très singulières, que j'introduirai sans présupposer de connaissances en physique quantique. Les hypothèses de la théorie usuelle (phi-irréductibilité, etc.) ne sont pas satisfaites en général, et les propriétés de grandes déviations de ces trajectoires restent un problème ouvert.

Finite-sample statistical guarantees for learning dynamical systems in state-space form

Jeudi, 27 novembre 2025 - 10:15 - 11:15

In this talk, I will present an overview of recent results on finite-sample Probably Approximately Correct (PAC) and PAC-Bayesian bounds for learning partially observed dynamical systems in state-space form. For clarity, we begin with linear stochastic systems in discrete time, learned from a single trajectory, and then discuss extensions to more complex nonlinear settings.

On the derivation of mean-curvature flow and its fluctuations from microscopic interactions

On the derivation of mean-curvature flow and its fluctuations from microscopic interactions

Jeudi, 11 septembre 2025 - 11:30 - 12:30

The emergence of mean-curvature flow of an interface between different phases or populations is a phenomenon of long standing interest in statistical physics.  
In this talk, we review recent progress with respect to a class of reaction-diffusion stochastic particle systems on an $n$-dimensional lattice.
In such a process, particles can move across sites as well as be created/annihilated according to diffusion and reaction rates.  
These rates will be chosen so that there are two preferred particle mass density levels $a_1$, $a_2$ in `balance'.

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