English

A violation of the covariant entropy bound?

High Energy Physics - Theory 2015-05-06 v2 General Relativity and Quantum Cosmology

Abstract

Several arguments suggest that the entropy density at high energy density ρ\rho should be given by the expression s=Kρ/Gs=K\sqrt{\rho/G}, where KK is a constant of order unity. On the other hand the covariant entropy bound requires that the entropy on a light sheet be bounded by A/4GA/4G, where AA is the area of the boundary of the sheet. We find that in a suitably chosen cosmological geometry, the above expression for ss violates the covariant entropy bound. We consider different possible explanations for this fact; in particular the possibility that entropy bounds should be defined in terms of volumes of regions rather than areas of surfaces.

Keywords

Cite

@article{arxiv.1412.2618,
  title  = {A violation of the covariant entropy bound?},
  author = {Ali Masoumi and Samir D. Mathur},
  journal= {arXiv preprint arXiv:1412.2618},
  year   = {2015}
}

Comments

21 pages, 10 figures, More general derivation given, comments about viscosity effects added