# Asymmetric energy transfers in driven nonequilibrium systems and arrow of time

## TL;DR

This paper proposes that energy transfer from large to small scales in driven nonequilibrium systems breaks time symmetry, providing an alternative explanation for the arrow of time beyond entropy increase.

## Contribution

It introduces a multiscale energy transfer mechanism as a source of time irreversibility, illustrated through turbulence and applicable to quantum systems and the universe.

## Key findings

- Energy flows from large to small scales in driven systems.
- This flow breaks time reversal symmetry and detailed balance.
- The process can be viewed as a dissipation mechanism.

## Abstract

Fundamental interactions are either fully or nearly symmetric under time reversal. But macroscopic phenomena have a definite arrow of time. Though there is no convergence on the origin of time's preferential direction, many researchers believe that the direction of time is towards increasing entropy. In this paper, we provide an alternate point of view. In driven-dissipative nonequilibrium systems forced at large scale, the energy flows from large scales to dissipative scales. This generic and multiscale process breaks time reversal symmetry and principle of detailed balance, thus can yield an arrow of time. In this paper we propose that conversion of large-scale coherence to small-scales incoherence could be treated as a dissipation mechanism for generic physical systems. We illustrate the above processes using turbulence as an example. We argue that the above picture of time irreversibility could be employed to the universe and to many-body quantum systems.