# Physique statistique

### Professor Bernard Derrida

The two main research directions followed by Professor Bernard Derrida and his collaborators are the theory of disordered systems and non-equilibrium statistical physics.

In the theory of out-of-equilibrium, their research is focused on the calculation of large deviation functions of the density and of the current in non-equilibrium steady states, the study of travelling waves such as the Fisher-KPP equation and of several aspects of the branching Brownian motion.

Their present works on disordered systems are essentially devoted to the long standing problem of the depinning transition in presence of disorder and on the understanding of finite size corrections in presence of broken symmetry of replicas.

Their research is characterized by the introduction or the study of very simplified mathematical models like exclusion processes or random energy models, which have a rather broad field of applications such as traffic flow, growth of domains, genealogies, evolution in presence of selection.