Undoing the twist: the Ho\v{r}ava limit of Einstein-aether
General Relativity and Quantum Cosmology
2015-06-17 v2 Cosmology and Nongalactic Astrophysics
High Energy Physics - Theory
Abstract
We show that Ho\v{r}ava gravity can be obtained from Einstein-aether theory in the limit that the twist coupling constant goes to infinity, while holding fixed the expansion, shear and acceleration couplings. This limit helps to clarify the relation between the two theories, and allows Ho\v{r}ava results to be obtained from Einstein-aether ones. The limit is illustrated with several examples, including rotating black hole equations, PPN parameters, and radiation rates from binary systems.
Keywords
Cite
@article{arxiv.1310.5115,
title = {Undoing the twist: the Ho\v{r}ava limit of Einstein-aether},
author = {Ted Jacobson},
journal= {arXiv preprint arXiv:1310.5115},
year = {2015}
}
Comments
5 pages; v2: added discussion of inferences from the general form of the action, changed normalization of expansion coupling coefficient to simplify formulas, nearly coincides with PRD version