Hydrodynamic effective field theories with discrete rotational symmetry

TL;DR

This paper develops a hydrodynamic effective field theory for fluids with discrete rotational symmetry, analyzing anisotropic effects on thermodynamics and dissipation, applicable across various dimensions and symmetry groups.

Contribution

It introduces a comprehensive EFT framework for anisotropic fluids with discrete rotational symmetry, extending to arbitrary dimensions and symmetry groups.

Findings

Identifies new terms in hydrodynamic equations compatible with entropy current.

Shows anisotropy affects thermodynamic and dissipative properties.

Framework applicable to any spatial dimension and rotation group.

Abstract

We develop a hydrodynamic effective field theory on the Schwinger-Keldysh contour for fluids with charge, energy, and momentum conservation, but only discrete rotational symmetry. The consequences of anisotropy on thermodynamics and first-order dissipative hydrodynamics are detailed in some simple examples in two spatial dimensions, but our construction extends to any spatial dimension and any rotation group (discrete or continuous). We find many possible terms in the equations of motion which are compatible with the existence of an entropy current, but not with the ability to couple the fluid to background gauge fields and vielbein.