Prof. Oren Raz

The group studies the statistical mechanics of systems pushed away from thermal equilibrium, where the familiar guarantees of equilibrium thermodynamics no longer hold. A central thread is the dynamics of relaxation: how a system in contact with a thermal bath approaches its steady state, and why that approach can be sharply counterintuitive. The anomalous, or Mpemba, effect — in which a hotter system can cool faster than a colder one, and its heating-side analogues — serves as a concrete probe for the structure of relaxation in Markovian and stochastic thermodynamic models.

A second focus is periodically driven systems, where external time-dependent forcing competes with relaxation toward a bath. The group asks when such driving produces a genuine non-equilibrium steady state, how that state differs from an equilibrium one, and what general bounds constrain the work, dissipation, and response. This work connects to broader questions in stochastic thermodynamics — fluctuation relations, thermodynamic inequalities, and the cost of control — and matters because most physical, chemical, and biological processes operate out of equilibrium, where a predictive theory is still being assembled.