Geometrical methods in loop calculations and the three-point function

TL;DR

This paper reviews a geometrical approach to calculating N-point Feynman diagrams, focusing on the three-point function, including epsilon-expansion and analytical continuation across kinematic regions.

Contribution

It introduces a geometrical method for loop calculations and provides detailed analysis of the three-point function with all orders of epsilon-expansion.

Findings

Effective geometrical framework for N-point diagram calculations

Explicit epsilon-expansion for the three-point function

Method for analytical continuation across kinematic regions

Abstract

A geometrical way to calculate N-point Feynman diagrams is reviewed. As an example, the dimensionally-regulated three-point function is considered, including all orders of its epsilon-expansion. Analytical continuation to other regions of the kinematical variables is discussed.