Nonrelativistic superfluids in cosmology from a relativistic approach: Revisiting two formulations of superfluidity

TL;DR

This paper compares two formulations of superfluidity, demonstrating how the nonrelativistic two-fluid model can be derived from a relativistic effective field theory, with applications to cosmology and curved spaces.

Contribution

It provides a clear derivation of the nonrelativistic superfluid formalism from a relativistic theory, bridging condensed matter and cosmological models.

Findings

Recovery of Landau's two-fluid model from relativistic theory

Derivation of nonrelativistic superfluids in curved spaces

Accessible presentation for interdisciplinary readers

Abstract

Two formulations of superfluidity are reviewed: Landau's phenomenological two-fluid model and a relativistic effective field theory description. We demonstrate how the two-fluid formalism can be recovered from the nonrelativistic limit of the relativistic effective theory at finite temperatures. We show how self-gravitating, nonrelativistic superfluids are obtained from the Newtonian limit of the relativistic approach on curved spaces. The concepts are presented in an accessible manner for readers who may not be deeply familiar with superfluidity from a condensed matter perspective.