Entropy production at freeze-out from dissipative fluids

TL;DR

This paper investigates entropy production caused by shear viscosity during the continuous freeze-out process in a relativistic dissipative fluid, providing estimates based on fluid dynamics assumptions for a pion fluid.

Contribution

It introduces a model to estimate entropy production during continuous freeze-out in relativistic dissipative fluids, focusing on shear viscosity effects.

Findings

Entropy production is small during freeze-out.

Entropy production depends on freeze-out duration.

Results are specific to a relativistic massless pion fluid.

Abstract

Entropy production due to shear viscosity during the continuous freeze-out of a longitudinally expanding dissipative fluid is addressed. Assuming the validity of the fluid dynamical description during the continuous removal of interacting matter we estimated a small entropy production as function of the freeze-out duration and the ratio of dissipative to non-dissipative quantities in case of a relativistic massless pion fluid.