FeynGrav 4.0

Abstract

We present the new version of FeynGrav, a package that provides a set of tools to work with Feynman rules for gravity models. The new version addresses two principal issues and includes changes that improve user experience. Firstly, we present a more sophisticated implementation of the BRST formalism for general relativity and quadratic gravity, which results in a finite set of interaction rules between ghosts and gravitons. We also implement a realisation of a higher derivative gauge fixing term for quadratic gravity. Secondly, we implement Feynman rules for Cheung-Remmen variables. These variables present the general relativity action in a polynomial form and produce a finite set of Feynman rules. Lastly, we introduce some minor quality-of-life changes to the package to improve the user experience.