Expansion by regions: an overview

TL;DR

This paper reviews the expansion by regions method for multiloop Feynman integrals, explaining its geometric formulation and illustrating it with simple examples to facilitate understanding of the technique.

Contribution

It provides a clear overview of the expansion by regions strategy, emphasizing its geometric interpretation and practical application through illustrative examples.

Findings

The method simplifies multiloop integral expansions in specific limits.

Geometric language aids in understanding the expansion process.

Examples demonstrate the practical implementation of the strategy.

Abstract

A short review of expansion by regions is presented. It is a well-known strategy to obtain an expansion of a given multiloop Feynman integral in a given limit where some kinematic invariants and/or masses have certain scaling measured in powers of a given small parameter. Prescriptions of this strategy are formulated in a simple geometrical language and are illustrated through simple examples.