Universal ratio as lower bound

TL;DR

This paper refines the universal ratio c/tilde{c} in holography, conjectures it as a lower bound, and supports this with models and a proof connecting it to the C-Theorem.

Contribution

It introduces a refined definition of the universal ratio c/tilde{c} for non-CFT holographic theories and proves it as a lower bound.

Findings

The universal ratio c/tilde{c} is conjectured to be ≥ 1.

The conjecture is supported by the hard wall AdS/QCD and Pilch-Warner models.

A general proof is provided in multi-kink holographic backgrounds.

Abstract

We refine the definition of universal ratio c/\tilde{c} obtained via AdS/CFT correspondence as shown in arXiv:0801.2785 [hep-th], denoted as \gamma_c, and apply it to non-CFTs whose dual gravitational theory have metric of asymptotic AdS. We conjecture that \gamma_c=1 is the lower bound being saturated at high temperature regime and serves as an ordering parameter as energy scale varies. We test this conjecture with the hard wall AdS/QCD toy model and N=2* Pilch-Warner solution and find the agreement. At last, we make a connection with the C-Theorem and prove this conjecture in a general holographic background with multi-kink geometry.