FeynMG: a FeynRules extension for scalar-tensor theories of gravity

Sergio Sevillano Muñoz, Edmund J. Copeland, Peter Millington, Michael Spannowsky

Research output: Contribution to journalArticlepeer-review

83 Downloads (Pure)

Abstract

The ability to represent perturbative expansions of interacting quantum field theories in terms of simple diagrammatic rules has revolutionized calculations in particle physics (and elsewhere). Moreover, these rules are readily automated, a process that has catalyzed the rise of symbolic algebra packages. However, in the case of extended theories of gravity, such as scalar-tensor theories, it is necessary to precondition the Lagrangian to apply this automation or, at the very least, to take advantage of existing software pipelines. We present a Mathematica code FeynMG, which works in conjunction with the well-known package FeynRules, to do just that: FeynMG takes as inputs the FeynRules model file for a non-gravitational theory and a user-supplied gravitational Lagrangian. FeynMG provides functionality that inserts the minimal gravitational couplings of the degrees of freedom specified in the model file, determines the couplings of the additional tensor and scalar degrees of freedom (the metric and the scalar field from the gravitational sector), and preconditions the resulting Lagrangian so that it can be passed to FeynRules, either directly or by outputting an updated FeynRules model file. The Feynman rules can then be determined and output through FeynRules, using existing universal output formats and interfaces to other analysis packages.

Original languageEnglish
Article number109035
JournalComputer Physics Communications
Volume296
Early online date6 Dec 2023
DOIs
Publication statusPublished - 1 Mar 2024

Keywords

  • Feynman rules
  • Symbolic algebra
  • Scalar-tensor theories
  • High energy physics
  • FeynRules

Fingerprint

Dive into the research topics of 'FeynMG: a FeynRules extension for scalar-tensor theories of gravity'. Together they form a unique fingerprint.

Cite this