Out of equilibrium dynamics of classical and quantum complex systems

TL;DR

This paper discusses the complex behavior of classical and quantum systems out of equilibrium, emphasizing the lack of universal principles and the importance of identifying common features and laws in non-equilibrium physics.

Contribution

It provides a brief overview of the behavior and theoretical understanding of non-equilibrium systems, highlighting recent progress and the search for unified descriptions.

Findings

Identification of common features in non-equilibrium systems

Emergence of some general laws in out-of-equilibrium dynamics

Highlighting the complexity and diversity of non-equilibrium phenomena

Abstract

Equilibrium is a rather ideal situation, the exception rather than the rule in Nature. Whenever the external or internal parameters of a physical system are varied its subsequent relaxation to equilibrium may be either impossible or take very long times. From the point of view of fundamental physics no generic principle such as the ones of thermodynamics allows us to fully understand their behaviour. The alternative is to treat each case separately. It is illusionary to attempt to give, at least at this stage, a complete description of all non-equilibrium situations. Still, one can try to identify and characterise some concrete but still general features of a class of out of equilibrium problems - yet to be identified - and search for a unified description of these. In this report I briefly describe the behaviour and theory of a set of non-equilibrium systems and I try to highlight common features and some general laws that have emerged in recent years.