Integrable Quantum Hydrodynamics in Two Dimensional Phase Space

TL;DR

This paper explores the quantum hydrodynamics of a two-dimensional phase space liquid derived from the Calogero model, revealing how its symmetry algebra governs dynamics and connecting quantum and classical stochastic hydrodynamics.

Contribution

It clarifies the role of symmetry algebra in two-dimensional quantum hydrodynamics and relates it to classical stochastic hydrodynamics through the Calogero model.

Findings

Symmetry algebra of conserved quantities is expressed in phase space hydrodynamics.

Quantum hydrodynamics relates to classical stochastic hydrodynamics via stochastic quantization.

The approach may extend to study stochastic classical hydrodynamics.

Abstract

Quantum liquids in two dimensions represent interesting dynamical quantum systems for several reasons, among them the possibility of the existence of infinite hidden symmetries, such as conformal symmetry or the symmetry associated with area preserving diffeo-morphisms. It is known that when the symmetry algebra is large enough, symmetry may fully prescribe the dynamics. However, the way this is borne out in two dimensional hydrodynamics, both classical and quantum, is not fully understood. Here we take a step in clarifying this issue, by focusing on a particular example, namely that of a two dimensional phase space liquid which emerges when one considers the Calogero model, a many-body one-dimensional system interacting through an inverse square law potential. We demonstrate how the symmetry algebra of conserved quantities of the one dimensional system is expressed in terms of the incompressible Euler hydrodynamics of point vortices in phase space. Due to a formal relation between quantum hydrodynamics and classical stochastic hydrodynamics, which is inherent in the method of stochastic quantization, the ideas and methods developed here may also have application in the study of stochastic classical hydrodynamics, after suitable modifications.