On the Cardy-Verlinde Entropy Formula in Viscous Cosmology
Abstract
The results of the paper of Verlinde [hep-th/0008140], discussing the holographic principle in a radiation dominated universe, are extended when allowing the cosmic fluid to possess a bulk viscosity. This corresponds to a non-conformally invariant theory. The generalization of the Cardy-Verlinde entropy formula to the case of a viscous universe seems from a formal point of view to be possible, although we question on physical grounds some elements in this kind of theory, especially the manner in which the Casimir energy is evaluated. Our discussion suggests that for non-conformally invariant theories the holographic definition of Casimir energy should be modified.
Keywords
Cite
@article{arxiv.gr-qc/0110105,
title = {On the Cardy-Verlinde Entropy Formula in Viscous Cosmology},
author = {I. Brevik and S. D. Odintsov},
journal= {arXiv preprint arXiv:gr-qc/0110105},
year = {2009}
}
Comments
11 pages, LaTeX, no figures. Discussion added in Sec. 2. To appear in Phys. Rev. D