One-loop effective scalar-tensor gravity

Abstract

Non-minimal interactions are proven to be generated at the one-loop level in simple scalar-tensor gravity models. The John interaction from the Fab Four class is generated. The interaction affects the speed of gravitational waves in the contemporary Universe. Its role in low-energy phenomenology is discussed. Brans-Dicke-like interaction is generated in a non-minimal model. An opportunity to generate a dynamic low-energy Newton constant is addressed.

Beyond Horndeski interactions induced by quantum effects

“…A similar effect was found in paper [26]. In an analogy with [21] the paper addresses an effect that does not depend on the factorization scale.…”

“…At the one-loop level the model generates the desired non-minimal kinetic coupling [26]. To show that beyond Horndeski interactions are generated in a way similar to the non-minimal coupling we find the specific one-loop amplitude that generates a beyond Horndeski interaction.…”

“…It also should be noted that, unlike the other case [21], such an interaction is local and strongly suppressed. Because of this one can establish some empirical constraints on its coupling [26].…”

“…Recently it was found that a certain non-minimal interaction between the scalar field and gravity is dynamically induced at the one-loop level [26]. The effect is a complete analogy with the anomalous fermion dipole moment.…”

“…Quantum behavior of a gravity theory can be consistently described within effective field theory formalism [21,22,23]. Such an approach to gravity is well studied for general relativity and it allows one to obtain some verifiable predictions [24,25,26]. We also should note that one should not neglect the whole manifold of alternative approaches to quantum features of scalar-tensor theories [27,28,29,30,31,32,33,34].…”