On the radial expansion of tubular structures in a quark gluon plasma

TL;DR

This paper investigates the radial expansion dynamics of cylindrical energy density perturbations in a quark-gluon plasma using relativistic hydrodynamics, including ideal and viscous cases, with numerical solutions and analytical estimates.

Contribution

It introduces a novel analysis of tube expansion in QGP using perturbative hydrodynamics and derives equations governing the evolution of these perturbations.

Findings

Break wave equation describes ideal fluid perturbations.

Viscous effects lead to Burgers equation dynamics.

Estimated expansion timescales for the tubes.

Abstract

We study the radial expansion of cylindrical tubes in a hot QGP. These tubes are treated as perturbations in the energy density of the system which is formed in heavy ion collisions at RHIC and LHC. We start from the equations of relativistic hydrodynamics in two spatial dimensions and cylindrical symmetry and perform an expansion of these equations in a small parameter, conserving the nonlinearity of the hydrodynamical formalism. We consider both ideal and viscous fluids and the latter are studied with a relativistic Navier-Stokes equation. We use the equation of state of the MIT bag model. In the case of ideal fluids we obtain a breaking wave equation for the energy density fluctuation, which is then solved numerically. We also show that, under certain assumptions, perturbations in a relativistic viscous fluid are governed by the Burgers equation. We estimate the typical expansion time of the tubes.