Effective Temperatures in Driven Systems: Static vs. Time-Dependent Relations

TL;DR

This study compares static and dynamic definitions of effective temperature in driven glassy systems, finding surprising agreement over a wide range, indicating the need for a more comprehensive theoretical framework.

Contribution

It demonstrates that static linear response and time-dependent fluctuation-dissipation relations produce the same effective temperature in steady-state driven systems, challenging existing expectations.

Findings

Static and dynamic effective temperatures agree over two and a half decades.

Results suggest the need for a more complete theoretical framework.

Findings challenge the assumption that these definitions should differ.

Abstract

Using simulations of glassy systems under steady-state shear, we compare effective temperatures obtained from static linear response with those from time-dependent fluctuation-dissipation relations. Although these two definitions are not expected to agree, we show that they yield the same answer over two and a half decades of effective temperature. This suggests that a more complete conceptual framework is necessary for effective temperatures in steady-state driven systems.