Hidden Negative Energies in Strongly Accelerated Universes
Cosmology and Nongalactic Astrophysics
2013-03-05 v2 General Relativity and Quantum Cosmology
High Energy Physics - Theory
Abstract
We point out that theories of cosmological acceleration which have equation of state, w, such that 1+w is small but positive may still secretly violate the null energy condition. This violation implies the existence of observers for whom the background has infinitely negative energy densities, despite the fact that the perturbations are free of ghosts and gradient instabilities.
Keywords
Cite
@article{arxiv.1209.2961,
title = {Hidden Negative Energies in Strongly Accelerated Universes},
author = {Ignacy Sawicki and Alexander Vikman},
journal= {arXiv preprint arXiv:1209.2961},
year = {2013}
}
Comments
5 pages, 1 figure. v2 reflects version accepted for publication in PRD. Changes: additional discussion of gauge-dependence in perturbed cosmologies