Unitarity and the Vainshtein Mechanism

TL;DR

This paper examines how UV modes influence the low energy behavior of massive gauge theories with the Vainshtein mechanism, revealing that higher order corrections and UV completions significantly impact the screening effectiveness and strong coupling scales.

Contribution

It demonstrates that UV effects and higher order corrections alter the low energy dynamics of theories with the Vainshtein mechanism, challenging previous assumptions about screening and strong coupling.

Findings

UV modes significantly influence Goldstone sectors.

Higher order corrections affect the strong coupling scale.

Environmental effects may not fully cure bad UV behavior.

Abstract

We investigate low energy limits of massive gauge theories that feature the Vainshtein mechanism, focussing on the effects of the UV modes that are integrated out. It turns out that the Goldstone sectors are significantly influenced by the effects from such modes relative to the effective field theories where the irrelevant operators induced by heavy modes are simply cast aside. The effects of the consistently retained higher order corrections affect the strong coupling and show that the nature of the UV completion influences the low energy theory significantly. This casts doubts on the naively estimated environmental strong coupling scale, and on the effectiveness of the environmental enhancement of screening. The environmental effects by themselves might not suffice to cure the bad behavior of the theory beyond the vacuum cutoff.