A rederivation of the conformal anomaly for spin-1/2

TL;DR

This paper presents a new Feynman graph calculation to rederive the conformal anomaly for spin-1/2 fermions, providing a novel method to explore more complex quantum field theory cases.

Contribution

It introduces a genuine Feynman graph approach to derive the conformal anomaly for spin-1/2 fermions, enabling investigation of more complicated non-conformal theories.

Findings

Confirmed the known conformal anomaly result for spin-1/2 fermions

Developed a new Feynman graph calculation method

Facilitated future studies of quantum trace issues in non-conformal theories

Abstract

We rederive the conformal anomaly for spin-1/2 fermions by a genuine Feynman graph calculation, which has not been available so far. Although our calculation merely confirms a result that has been known for a long time, the derivation is new, and thus furnishes a method to investigate more complicated cases (in particular concerning the significance of the quantum trace of the stress tensor in non-conformal theories) where there remain several outstanding and unresolved issues.