Anisotropic hydrodynamics -- basic concepts

TL;DR

This paper reviews anisotropic hydrodynamics, a framework designed to better model the early-time dynamics of quark-gluon plasma by accounting for large local momentum-space anisotropies.

Contribution

It introduces and discusses the basic concepts of anisotropic hydrodynamics, emphasizing its advantages over traditional viscous hydrodynamics in high anisotropy conditions.

Findings

Provides a conceptual overview of anisotropic hydrodynamics.

Highlights the framework's ability to handle large momentum-space anisotropies.

Connects phenomenological and microscopic perspectives.

Abstract

Due to the rapid longitudinal expansion of the quark-gluon plasma created in relativistic heavy ion collisions, potentially large local rest frame momentum-space anisotropies are generated. The magnitude of these momentum-space anisotropies can be so large as to violate the central assumption of canonical viscous hydrodynamical treatments which linearize around an isotropic background. In order to better describe the early-time dynamics of the quark gluon plasma, one can consider instead expanding around a locally anisotropic background which results in a dynamical framework called anisotropic hydrodynamics. In this proceedings contribution we review the basic concepts of the anisotropic hydrodynamics framework presenting viewpoints from both the phenomenological and microscopic points of view.