Critical Dynamics of Superfluids

TL;DR

This paper develops a relativistic effective field theory for nearly critical superfluids, introducing an additional coefficient and validating it through alternative derivations and holographic comparisons.

Contribution

It presents a new relativistic effective field theory for superfluids, including an extra coefficient, and offers an alternative derivation using the Keldysh-Schwinger framework.

Findings

Identification of an additional coefficient in the superfluid effective theory.

Validation of the theory through holographic computations.

Consistency with earlier hydrodynamic models.

Abstract

We use standard techniques of hydrodynamics to construct a relativistic effective field theory for the low energy dynamics of nearly critical superfluids. In an appropriate non-relativistic limit, our theory predicts an additional coefficient when compared and contrasted to earlier work of Khalatnikov and Lebedev. In addition, we provide an alternative derivation of the same effective theory, using the Keldysh-Schwinger framework for non-equilibrium systems. Finally, we comment on the comparison with the results of an appropriate holographic computation presented in a companion paper. This provides further evidence in support of the theory we propose and confirms the existence of the extra coefficient we identified.