2003/04/28 by Jean-Pierre Eckmann
Physics and Astronomy · Mathematics · #math-ph #math.MP #msc:82C22 #msc:60H15
published as Proceedings of the ICM, Beijing 2002, vol. 3, 409--418
arxiv created 2003/04/28 · arxiv updated 2009/11/30
The mathematical physics of mechanical systems in thermal equilibrium is a well studied, and relatively easy, subject, because the Gibbs distribution is in general an adequate guess for the equilibrium state. On the other hand, the mathematical physics of \em non-equilibrium systems, such as that of a chain of masses connected with springs to two (infinite) heat reservoirs is more difficult, precisely because no such \em a priori guess exists. Recent work has, however, revealed that under quite general conditions, such states can not only be shown to exist, but are \em unique, using the Hörmander conditions and controllability. Furthermore, interesting properties, such as energy flux, exponentially fast convergence to the unique state, and fluctuations of that state have been successfully studied. Finally, the ideas used in these studies can be extended to certain stochastic PDE's using Malliavin calculus to prove regularity of the process.