Absence of thermalization for systems with long-range interactions coupled to a thermal bath

TL;DR

This paper studies long-range interacting systems coupled to thermal baths, revealing anomalous energy flux behaviors and lack of thermalization, explained via Vlasov dynamics applicable across various physical contexts.

Contribution

It demonstrates that long-range interactions lead to non-thermalizing dynamics with energy flux anomalies, extending understanding beyond short-range systems.

Findings

Energy flux anomalies observed between system and bath.

System temperature can increase despite higher initial temperature.

Vlasov framework explains the non-thermalization phenomenon.

Abstract

We investigate the dynamics of a small long-range interacting system, in contact with a large long-range thermal bath. Our analysis reveals the existence of striking anomalies in the energy flux between the bath and the system. In particular, we find that the evolution of the system is not influenced by the kinetic temperature of the bath, as opposed to what happens for short-range collisional systems. As a consequence, the system may get hotter also when its initial temperature is larger than the bath temperature. This observation is explained quantitatively in the framework of the collisionless Vlasov description of toy models with long-range interactions and shown to be valid whenever the Vlasov picture applies, from cosmology to plasma physics.