Expansion by regions: an overview

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.

Comments: 13 pages, 3 figures, published in "Anti-Differentiation and the Calculation of Feynman Amplitudes", ed. J. Blümlein and C. Schneider, Springer 2021, doi:10.1007/978-3-030-80219-6. arXiv admin note: text overlap with arXiv:1809.04325