Quantum Field Theory of Fluids

TL;DR

This paper develops a quantum field theory framework for fluids, showing that quantum perfect fluids can be consistently described as low-energy effective theories with unique quantum behaviors at low temperatures.

Contribution

It introduces a novel quantum field theory formulation for fluids, highlighting the role of vortex modes and providing evidence for a consistent quantum fluid model.

Findings

Quantum perfect fluids can be formulated as effective field theories.

Correlation functions support the consistency of the quantum fluid model.

Quantum behavior in fluids differs significantly from classical fluids and quantum fields.

Abstract

The quantum theory of fields is largely based on studying perturbations around non-interacting, or free, field theories, which correspond to a collection of quantum-mechanical harmonic oscillators. The quantum theory of an ordinary fluid is `freer', in the sense that the non-interacting theory also contains an infinite collection of quantum-mechanical free particles, corresponding to vortex modes. By computing a variety of correlation functions at tree- and loop-level, we give evidence that a quantum perfect fluid can be consistently formulated as a low-energy, effective field theory. We speculate that the quantum behaviour is radically different to both classical fluids and quantum fields, with interesting physical consequences for fluids in the low temperature regime.