Vainshtein in the UV and a Wilsonian analysis of derivatively coupled scalars

TL;DR

This paper investigates the UV behavior of Vainshtein screening in scalar theories, using Wilsonian and non-perturbative RG methods, revealing quantum correction suppression and questioning classicalisation as a UV completion.

Contribution

It provides a combined Wilsonian and non-perturbative RG analysis of derivatively coupled scalars, highlighting quantum correction suppression and challenging classicalisation as a UV completion.

Findings

Quantum corrections are suppressed within the Vainshtein radius.

Classicalisation may not be a viable UV completion due to low strong coupling scale.

The study offers insights into the UV behavior of modified gravity theories.

Abstract

In the first part of this paper we critically examine the ultra-violet implications of theories that exhibit Vainshtein screening, taking into account both the standard Wilsonian perspective as well as more exotic possibilities. Aspects of this discussion draw on results from the second part of the paper in which we perform a general study of derivatively coupled scalar theories using non-perturbative exact renormalisation group techniques, which are of interest independently of their application to modified gravity. In this context, we demonstrate the suppression of quantum corrections within the Vainshtein radius and discuss the potential relation with the classicalisation conjecture. We question whether the latter can be considered a realistic candidate for UV completion of large-scale modifications of gravity on account of a dangerously low classicalisation/strong coupling scale.