Three-Point Spectral Density in QED and the Ward Identity at Finite Temperature

TL;DR

This paper derives spectral representations for QED 3-point functions at finite temperature, calculates spectral densities in the hard thermal loop approximation, and discusses Ward identities, comparing results with hot QCD.

Contribution

It provides explicit spectral density calculations for QED 3-point functions at finite temperature within the real time formalism, highlighting Ward identity compliance.

Findings

Spectral densities derived in the hard thermal loop approximation.

Ward identities hold for retarded and advanced functions.

Comparison with hot QCD results shows similarities and differences.

Abstract

We derive the spectral representations of QED 3-point functions and then explicitly calculate the 3-point spectral densities in hard thermal loop approximation within the real time formalism. The Ward identities obeyed by the retarded and advanced 2- and 3-point functions are discussed. We compare our results with those for hot QCD .