Alvise Bastianello
(Technical University Munich)

 

Abstract:
The thermodynamics of classical nonlinear waves is a notoriously hard problem, even for integrable models. The soliton gas picture lifts the zero-density solution of the model to a phenomenological macroscopic description, regarding the system as a gas of particles of finite width. In this talk, I will discuss how this simple approach fails in systems with extended solitons, and I will offer semiclassical limits of quantum integrable field theories as an alternative and safe route to their exact thermodynamics. With this machinery, I will solve the long-standing problem of building the exact thermodynamics of the Landau-Lifschitz model, a classical integrable spin chain, and discuss future perspectives disclosed by these findings.