We argue that higher-curvature terms in the gravitational Lagrangian lead, via non-relativistic
gauge-gravity duality, to nite renormalization of the dynamical exponent of the dual conformal
eld theory. Our argument includes a proof of the non-renormalization of the Schr odinger
and Lifshitz metrics beyond rescalings of their parameters, directly generalizing the AdS case.
We use this e ect 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.
Province of Ontario Ministry of Research & Innovation
Industry Canada
National Science and Engineering Research Council of Canada
Department of Energy