Causal construction of the massless vertex diagram

TL;DR

This paper presents a method for constructing the massless one-loop vertex diagram using causal principles in configuration space, enabling direct derivation of dispersive relations in momentum space.

Contribution

It introduces a novel causal construction approach for the massless vertex diagram, linking configuration space causality with momentum space dispersive relations.

Findings

Successfully constructs the massless vertex diagram using causal methods.

Establishes a direct connection between configuration space causality and momentum space dispersive relations.

Provides a new framework for analyzing massless quantum field diagrams.

Abstract

The massless one-loop vertex diagram is constructed by exploiting the causal structure of the diagram in configuration space, which can be translated directly into dispersive relations in momentum space.