Revisiting the cuscuton as a Lorentz-violating gravity theory

Bhattacharyya, Jishnu; Coates, Andrew; Colombo, Mattia; Gümrükçüoğlu, A. Emir; Sotiriou, Thomas P.

Abstract

The cuscuton is a scalar field with infinite speed of propagation. It was introduced in the context of cosmology but it has also been claimed to resemble Horava gravity in a certain limit. Here we revisit the cuscuton theory as a Lorentz-violating gravity theory. We clarify its relation with Horava gravity and Einstein-æther theory, analyze its causal structure, and consider its initial value formulation. Finally, we discuss to which extent the cuscuton theory can be used as a proxy for Horava gravity in the context of gravitational collapse and formation of universal horizons.

• Journal Article Type: Article
• Acceptance Date: Feb 16, 2018
• Publication Date: Mar 20, 2018
• Deposit Date: Apr 12, 2018
• Publicly Available Date: Apr 12, 2018
• Journal: Physical Review D
• Print ISSN: 2470-0010
• Electronic ISSN: 2470-0010
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 97
• Issue: 6
• DOI: https://doi.org/10.1103/PhysRevD.97.064020
• Public URL: https://nottingham-repository.worktribe.com/output/920565
• Publisher URL: https://journals.aps.org/prd/abstract/10.1103/PhysRevD.97.064020