Saving the Coherent State Path Integral

TL;DR

This paper identifies issues in coherent state path integrals caused by high frequency propagator structures and proposes modifications to obtain accurate thermodynamic results across various physical systems.

Contribution

It introduces a method to correct spurious results in coherent state path integrals by revisiting the discrete time formalism and adjusting the expressions for thermodynamic quantities.

Findings

Corrected expressions yield accurate thermodynamic calculations.

High frequency structures cause spurious results in standard approaches.

Method applicable to Bose gases and spin systems.

Abstract

By returning to the underlying discrete time formalism, we relate spurious results in coherent state path integral calculations to the high frequency structure of their propagators. We show how to modify the standard expressions for thermodynamic quantities to yield correct results. These expressions are relevant to a broad range of physical problems, from the thermodynamics of Bose lattice gases to the dynamics of spin systems.