R-Charged Black Holes and Holographic Optics

TL;DR

This paper investigates the optical properties of R-charged black holes via holography, revealing negative refraction phenomena through numerical analysis of momentum-dependent correlation functions.

Contribution

It constructs decoupled master variables for vector modes in R-charged black holes, enabling computation of momentum-dependent correlation functions beyond hydrodynamics.

Findings

Negative index of refraction observed in all cases

Numerical analysis of correlation functions performed

Master variables constructed for decoupling equations

Abstract

We analyze momentum dependent vector modes in the context of gauge theories dual to R-charged black holes in $D=4$, $5$ and $7$. For a variety of examples, the master variables are constructed, for which the linearized equations for the perturbations decouple. These allow for the computation of momentum dependent correlation functions. Away from the hydrodynamic limit, numerical analysis using the decoupled equations of motion is used to obtain the analogues of the Depine-Lakhtakia (DL) index. For specified ranges of frequencies, a negative index of refraction is seen to occur in all cases.