Virial coefficients from 2+1 dimensional QED effective actions at finite temperature and density

TL;DR

This paper calculates virial coefficients for particles in 2+1 dimensional QED under finite temperature and density, highlighting the role of gauge invariance and the parameter theta in interpolating between fermionic and bosonic behaviors.

Contribution

It introduces a method to derive virial coefficients from effective actions in 2+1D QED, emphasizing the significance of the gauge parameter theta for large gauge invariance.

Findings

Virial coefficients depend on the gauge parameter theta.

Variation of theta can interpolate between fermionic and bosonic coefficients.

Coefficients are singular at theta=pi/2.

Abstract

From spinor and scalar 2+1 dimensional QED effective actions at finite temperature and density in a constant magnetic field background, we calculate the corresponding virial coefficients for particles in the lowest Landau level. These coefficients depend on a parameter theta related to the time-component of the gauge field, which plays an essential role for large gauge invariance. The variation of the parameter theta might lead to an interpolation between fermionic and bosonic virial coefficients, although these coefficients are singular for theta=pi/2.