English

State of matter at high density and entropy bounds

General Relativity and Quantum Cosmology 2015-12-09 v1

Abstract

Entropy of all systems that we understand well is proportional to their volumes except for black holes given by their horizon area. This makes the microstates of any quantum theory of gravity drastically different from the ordinary matter. Because of the assumption that black holes are the maximum entropy states there have been many conjectures that put the area, defined one way or another, as a bound on the entropy in a given region of spacetime. Here we construct a simple model with entropy proportional to volume which exceeds the entropy of a single black hole. We show that a homogeneous cosmology filled with this gas exceeds one of the tightest entropy bounds, the covariant entropy bound and discuss the implications.

Keywords

Cite

@article{arxiv.1505.06787,
  title  = {State of matter at high density and entropy bounds},
  author = {Ali Masoumi},
  journal= {arXiv preprint arXiv:1505.06787},
  year   = {2015}
}

Comments

This essay was written for the 2015 Gravity Research Foundation essay competition and received an honorable mention