Entropy bounds in cosmology and conformal field theories

TL;DR

This paper investigates the entropy-to-energy ratio in conformal field theories, establishing bounds for free and strongly coupled cases, and explores their thermodynamic similarities with two-dimensional CFTs.

Contribution

It provides new bounds on the entropy-energy ratio in various conformal field theories, including free and strongly coupled cases with AdS duals, and highlights thermodynamic parallels with 2D CFTs.

Findings

Entropy-to-energy ratio is bounded in free CFTs.

Strongly coupled CFTs with AdS duals obey Verlinde bound even with rotation.

Thermodynamic formulas resemble those of two-dimensional CFTs.

Abstract

We study the ratio of the entropy to the total energy in conformal field theories at finite temperature. For the free field realizations of N=4 super Yang-Mills theory in D=4 and the (2,0) tensor multiplet in D=6, the ratio is bounded from above. The corresponding bounds are less stringent than the recently proposed Verlinde bound. For strongly coupled CFTs with AdS duals, we show that the ratio obeys the Verlinde bound even in the presence of rotation. For such CFTs, we point out an intriguing resemblance in their thermodynamic formulas with the corresponding ones of two-dimensional CFTs. The discussion is based on hep-th/0101076.