Metric anisotropies and emergent anisotropic hydrodynamics

Abstract

Expansion of a locally equilibrated fluid is considered in an anisotropic space-time given by Bianchi type I metric. Starting from isotropic equilibrium phase-space distribution function in the local rest frame, we obtain expressions for components of the energy-momentum tensor and conserved current, such as number density, energy density and pressure components. In the case of an axissymmetric Bianchi type I metric, we show that they are identical to that obtained within the setup of anisotropic hydrodynamics. We further consider the case when Bianchi type I metric is a vacuum solution of Einstein equation: the Kasner metric. For axis-symmetric Kasner metric, we discuss the implications of our results in the context of anisotropic hydrodynamics.

Non-perturbative rheological behavior of a far-from-equilibrium expanding plasma

“…The latter explains a recently found solution in Ref. [48]. At this point, the longitudinal pressure is maximum P L = ε, which in turn causes a huge amount of pressure along the z-direction due to ξ 0 → −1, while there is a slowdown in the transverse direction because P T = 0.…”