On the motion of a body in thermal equilibrium immersed in a perfect gas

ESAIM: M2AN has started a new practice of occasionally selecting certain papers as "Highlight" papers. The papers so designated we believe will be of particular interest to our readership due to the topic or approach pursued or perhaps the reach and implications of the results. Highlight papers will be briefly introduced by an Editor-in-Chief, and will be available (without charge, and indefinitely) on the ESAIM: M2AN electronic repository.

Understanding the microscopic picture of macroscopic phenomena is a long-term mathematical challenge. Important progress has been made in recent years in several different domains. This Highlight paper addresses the question of the modelling of friction at the microscopic scale: it studies the motion of a body immersed in a gas which experiences viscous friction owing to collisions with the gas molecules. In the case of diffusive collisions, the study establishes the rate at which the velocity of the body approaches its equilibrium value, and relates this rate to the recollisions of the gas molecules with the surface of the body. Such a study exemplifies the crucial role played by sophisticated mathematical arguments in the intimate understanding, and appropriate modelling, of physical issues.

Claude Le Bris, and Anthony T. Patera

On the motion of a body in thermal equilibrium immersed in a perfect gas
Kazuo Aoki, Guido Cavallaro, Carlo Marchioro and Mario Pulvirenti
ESAIM: M2AN 42 (2008) 263-275