Analytical explorations of thermalization in simple model systems

• Applicant: Professor Dr. Peter Reimann
• Subject Area: Statistical Physics, Nonlinear Dynamics, Complex Systems, Soft and Fluid Matter, Biological Physics
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 575546997

One of the most successful concepts in theoretical physics is the description of systems at thermal equilibrium by means of some suitably chosen canonical ensemble. Why this recipe works so well is still not satisfactorily understood. The main objective of this project is to achieve some progress in this direction. Specifically, we will show that an initial nonequilibrium state evolves in such a way that it is after sufficiently long times practically (experimentally) indistinguishable from the pertinent canonical ensemble. In doing so, the salient point is that only the basic laws of quantum mechanics may be utilized, but not any kind of additional postulate, hypothesis, or other type of unproven assumption. To reasonably limit the expected difficulties, we will mainly focus on particularly simple model systems and initial conditions, amounting to a so-called rethermalization scenario for noninteracting integrable models after a local quantum quench.

• DFG Programme: Research Grants