Entropy flow of a perfect fluid in (1+1) hydrodynamics

TL;DR

This paper derives exact formulas for entropy flow in (1+1) relativistic hydrodynamics of a perfect fluid using Khalatnikov potential, with analytical solutions and applications to heavy-ion collision phenomenology.

Contribution

It provides the first exact general formulae for entropy flow as a function of temperature in (1+1) hydrodynamics of a perfect fluid.

Findings

Derived explicit analytical solutions for entropy flow dS/dy.

Provided general formulae applicable to long hydrodynamic evolutions.

Discussed phenomenological implications for heavy-ion collisions.

Abstract

Using the formalism of the Khalatnikov potential, we derive exact general formulae for the entropy flow dS/dy, where y is the rapidity, as a function of temperature for the (1+1) relativistic hydrodynamics of a perfect fluid. We study in particular flows dominated by a sufficiently long hydrodynamic evolution, and provide an explicit analytical solution for dS/dy. We discuss the theoretical implications of our general formulae and some phenomenological applications for heavy-ion collisions.