Proof of universality of electrical conductivity at finite chemical potential
arXiv:1011.3499 · doi:10.1007/JHEP02(2011)073
Abstract
It was proposed in arXiv:1008.2944 that, for certain gauge theories with gravity duals, electrical conductivity at finite chemical potential is universal. Here we provide a general proof that, when matter stress tensor satisfies a compact constraint, electrical conductivity is universal. We further elaborate our result with several conformal as well as non-conformal gauge theories. We also discuss how boundary conductivity and universal conductivity of stretched horizon are related.
23 pages, minor modification, Version published in JHEP