Lorentz violation, gravity, dissipation and holography

Abstract

We reconsider Lorentz Violation (LV) at the fundamental level. We argue that Lorentz Violation is intimately connected with gravity and that LV couplings in QFT must always be fields in a gravitational sector. Diffeomorphism covariance, implementing general charnges of frame, is 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-trivially on two characteristic exponents, the Lifshitz exponent and the hyperscaling violation exponent.

Non-relativistic holography from Hořava gravity

“…In this way φ can be used to define the preferred foliation by a global time, and is referred to as the khronon [18,20]. This view of Hořava gravity as GR with diffeomorphism invariance broken by a background field has also been recently emphasized in [63].…”

Heavy Quark Potential with Hyperscaling Violation

“…Let us begin with a brief review of the background in [25]. It has been argued that the Lorentz invariance is broken in this background metric.…”

“…The geometry is in Rindler coordinates when = 0 and = 1. Usually, the above special solutions violate the Gubser bound conditions [25]. In addition, the pure Lifshitz case is related to = 0.…”

“…As we know, Lorentz symmetry represents a foundation of both general relativity and the standard model, so one may expect new physics from Lorentz invariance violation. For that reason, the metrics with hyperscaling violation have been used to describe the string theory [21][22][23][24][25] and holographic superconductors [26][27][28][29] as well as QCD [30][31][32].…”

“…In the next section, the backgrounds of the hyperscaling violation theories in [25] are briefly reviewed. In Section 3, we study the heavy quark potential in these backgrounds in terms of the and parameters.…”