Orateur
Zhe Chen
(MAP5, CNRS, Université Paris Cité)
Description
The classical Boltzmann equation models dilute gases, where particles are treated as mass points and collisions are local in space. For dense gases and related nonlocal models, such as Enskog, soft-sphere, and Povzner-type equations, collisions couple particles located at different spatial points. This spatial delocalization makes the usual local conservation and entropy structures less direct. In this talk, I will introduce a general framework for delocalized collision operators and explain how their conservation laws can be recovered through suitable spatial and velocity fluxes. I will also present a local entropy inequality and its connection with the H-theorem for dense-gas models.