Evolution and spherical collapse in Einstein-Æther theory and Hořava gravity
We compare the initial value formulation of the low-energy limit of (nonprojectable) Hořava gravity to that of Einstein-æther theory when the æther is assumed to be hypersurface orthogonal at the level of the field equations. This comparison clearly highlights a crucial difference in the causal stru...
| Main Authors: | , , , |
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| Format: | Article |
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American Physical Society
2016
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| Online Access: | https://eprints.nottingham.ac.uk/39494/ |
| _version_ | 1848795849911435264 |
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| author | Bhattacharyya, Jishnu Coates, Andrew Colombo, Mattia Sotiriou, Thomas P. |
| author_facet | Bhattacharyya, Jishnu Coates, Andrew Colombo, Mattia Sotiriou, Thomas P. |
| author_sort | Bhattacharyya, Jishnu |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | We compare the initial value formulation of the low-energy limit of (nonprojectable) Hořava gravity to that of Einstein-æther theory when the æther is assumed to be hypersurface orthogonal at the level of the field equations. This comparison clearly highlights a crucial difference in the causal structure of the two theories at the nonperturbative level: in Hořava gravity evolution equations include an elliptic equation that is not a constraint relating initial data but needs to be imposed on each slice of the foliation. This feature is absent in Einstein-æther theory. We discuss its physical significance in Hořava gravity. We also focus on spherical symmetry, and we revisit existing collapse simulations in Einstein-æther theory. We argue that they have likely already uncovered the dynamical formation of a universal horizon and that they can act as evidence that this horizon is indeed a Cauchy horizon in Hořava gravity. |
| first_indexed | 2025-11-14T19:38:38Z |
| format | Article |
| id | nottingham-39494 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T19:38:38Z |
| publishDate | 2016 |
| publisher | American Physical Society |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-394942020-05-04T17:40:44Z https://eprints.nottingham.ac.uk/39494/ Evolution and spherical collapse in Einstein-Æther theory and Hořava gravity Bhattacharyya, Jishnu Coates, Andrew Colombo, Mattia Sotiriou, Thomas P. We compare the initial value formulation of the low-energy limit of (nonprojectable) Hořava gravity to that of Einstein-æther theory when the æther is assumed to be hypersurface orthogonal at the level of the field equations. This comparison clearly highlights a crucial difference in the causal structure of the two theories at the nonperturbative level: in Hořava gravity evolution equations include an elliptic equation that is not a constraint relating initial data but needs to be imposed on each slice of the foliation. This feature is absent in Einstein-æther theory. We discuss its physical significance in Hořava gravity. We also focus on spherical symmetry, and we revisit existing collapse simulations in Einstein-æther theory. We argue that they have likely already uncovered the dynamical formation of a universal horizon and that they can act as evidence that this horizon is indeed a Cauchy horizon in Hořava gravity. American Physical Society 2016-03-23 Article PeerReviewed Bhattacharyya, Jishnu, Coates, Andrew, Colombo, Mattia and Sotiriou, Thomas P. (2016) Evolution and spherical collapse in Einstein-Æther theory and Hořava gravity. Physical Review D, 93 (6). 64056/1-64056/10. ISSN 2470-0029 http://dx.doi.org/10.1103/PhysRevD.93.064056 doi:10.1103/PhysRevD.93.064056 doi:10.1103/PhysRevD.93.064056 |
| spellingShingle | Bhattacharyya, Jishnu Coates, Andrew Colombo, Mattia Sotiriou, Thomas P. Evolution and spherical collapse in Einstein-Æther theory and Hořava gravity |
| title | Evolution and spherical collapse in Einstein-Æther theory and Hořava gravity |
| title_full | Evolution and spherical collapse in Einstein-Æther theory and Hořava gravity |
| title_fullStr | Evolution and spherical collapse in Einstein-Æther theory and Hořava gravity |
| title_full_unstemmed | Evolution and spherical collapse in Einstein-Æther theory and Hořava gravity |
| title_short | Evolution and spherical collapse in Einstein-Æther theory and Hořava gravity |
| title_sort | evolution and spherical collapse in einstein-æther theory and hořava gravity |
| url | https://eprints.nottingham.ac.uk/39494/ https://eprints.nottingham.ac.uk/39494/ https://eprints.nottingham.ac.uk/39494/ |