Bjorken expansion in the isotropic Kasner spacetime

TL;DR

This paper proposes a model of isotropic quark-gluon plasma expansion within curved Kasner spacetime, linking bulk viscosity to entropy production and black hole interior physics.

Contribution

It introduces a novel isotropic expansion model in curved spacetime with a time-dependent bulk viscosity, connecting cosmological and black hole interior properties.

Findings

Bulk viscosity varies with time in the model.

The model explains high entropy per baryon in the universe.

Bulk viscosity matches that of anisotropic black hole interiors.

Abstract

An isotropic expansion for the QGP is proposed in curved Kasner spacetime for an experimental configuration with three dimensional set of beams. The fluid of relativistic particles has no shear viscosity but the nonzero bulk viscosity $\zeta$ is time dependent and its value could explain the enormous entropy per baryon of our Universe. In addition, $\zeta$ equals the bulk viscosity of the anisotropic compressible fluid conjectured for the interior of a black hole.