Quantum corrections for the cubic Galileon in the covariant language

TL;DR

This paper computes quantum corrections to the cubic Galileon theory including gravity effects, revealing new interactions and higher-operators, using a covariant, gauge-invariant 1-loop approach.

Contribution

It provides the first explicit covariant, background- and gauge-invariant calculation of quantum corrections in the cubic Galileon theory with gravity effects.

Findings

Quantum gravity influences the cubic Galileon, generating new interactions.

Higher-operators emerge in the effective action due to quantum effects.

The covariant approach ensures gauge invariance and explicit calculations.

Abstract

We present for the first time an explicit exposition of quantum corrections within the cubic Galileon theory including the effect of quantum gravity, in a background- and gauge-invariant manner, employing the field-reparametrisation approach of the covariant effective action at 1-loop. We show that the consideration of gravitational effects in combination with the non-linear derivative structure of the theory reveals new interactions at the perturbative level, which manifest themselves as higher-operators in the associated effective action, which' relevance is controlled by appropriate ratios of the cosmological vacuum and the Galileon mass scale. The significance and concept of the covariant approach in this context is discussed, while all calculations are explicitly presented.