Topology and Dark Energy: Testing Gravity in Voids
Abstract
Modified gravity has garnered interest as a backstop against dark matter and dark energy (DE). As one possible modification, the graviton can become massive, which introduces a new scalar field - here with a Galileon-type symmetry. The field can lead to a nontrivial equation of state (EOS) of DE which is density-and-scale-dependent. Tension between Type Ia supernovae and Planck could be reduced. In voids the scalar field dramatically alters the EOS of DE, induces a soon-observable gravitational slip between the two metric potentials, and develops a topological defect (domain wall) due to a nontrivial vacuum structure for the field.
Cite
@article{arxiv.1304.5239,
title = {Topology and Dark Energy: Testing Gravity in Voids},
author = {Douglas Spolyar and Martin Sahlén and Joe Silk},
journal= {arXiv preprint arXiv:1304.5239},
year = {2013}
}
Comments
Revised version, added detail, conclusions unchanged, matches PRL published version in content. 4 pages, 2 figures