Lorentz violation, Gravity, Dissipation and Holography

TL;DR

This paper explores the deep connection between Lorentz violation, gravity, and holography, showing that LV couplings are gravitational fields and analyzing energy dissipation in strongly coupled theories with gravity duals.

Contribution

It demonstrates that Lorentz violation is linked to gravity and must involve tensorial couplings, providing a holographic computation of energy dissipation rates in scale-invariant regimes.

Findings

LV couplings are gravitational fields transforming as tensors.

Energy dissipation is a generic feature of LV in QFT.

Dissipation rate depends on Lifshitz and hyperscaling exponents.

Abstract

We reconsider Lorentz Violation (LV) at the fundamental level. We show that Lorentz Violation is intimately connected with gravity and that LV couplings in QFT must always be fields in a gravitational sector. Diffeomorphism invariance must be intact and the LV couplings transform as tensors under coordinate/frame changes. Therefore searching for LV is one of the most sensitive ways of looking for new physics, either new interactions or modifications of known ones. Energy dissipation/Cerenkov radiation is shown to be a generic feature of LV in QFT. A general computation is done in strongly coupled theories with gravity duals. It is shown that in scale invariant regimes, the energy dissipation rate depends non-triviallly on two characteristic exponents, the Lifshitz exponent and the hyperscaling violation exponent.