1/N Effects in Non-Relativistic Gauge-Gravity Duality

TL;DR

This paper explores how higher-curvature gravitational terms affect the dynamical exponent in non-relativistic gauge-gravity duality, leading to new string-theory duals and predictions for viscosity/entropy ratios that slightly violate the KSS bound.

Contribution

It demonstrates that higher-curvature terms cause finite renormalization of the dynamical exponent and constructs new duals for non-relativistic systems with non-integer exponents.

Findings

Finite renormalization of the dynamical exponent due to higher-curvature terms.

Construction of string-theory duals for non-relativistic critical systems.

Predicted viscosity/entropy ratios that weakly violate the KSS bound.

Abstract

We argue that higher-curvature terms in the gravitational Lagrangian lead, via non-relativistic gauge-gravity duality, to finite renormalization of the dynamical exponent of the dual conformal field theory. Our argument includes a proof of the non-renormalization of the Schrodinger and Lifshitz metrics beyond rescalings of their parameters, directly generalizing the AdS case. We use this effect to construct string-theory duals of non-relativistic critical systems with non-integer dynamical exponents, then use these duals to predict the viscosity/entropy ratios of these systems. The predicted values weakly violate the KSS bound.