Testing gravity with black holes
<p>In this thesis, I study the ways in which modified theories of gravity might be tested for using black holes. In particular, I focus on ways in which the gravitational waves emitted during the ‘ringdown’ of a perturbed black hole may be affected.</p> <p>I will develop and demons...
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| Format: | Thesis |
| Language: | English |
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2019
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| _version_ | 1817931837723377664 |
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| author | Tattersall, O |
| author2 | Ferreira, P |
| author_facet | Ferreira, P Tattersall, O |
| author_sort | Tattersall, O |
| collection | OXFORD |
| description | <p>In this thesis, I study the ways in which modified theories of gravity might be tested for using black holes. In particular, I focus on ways in which the gravitational waves emitted during the ‘ringdown’ of a perturbed black hole may be affected.</p> <p>I will develop and demonstrate the use of a framework for analysing the evolution of perturbations in arbitrary modified gravity theories in both cosmological and black hole backgrounds. I will use this to show that the characteristic Quasi-normal mode (QNM) spectrum of frequencies for the gravitational waves emitted from a perturbed black hole may be altered even in the case that the background black hole is identical to a general relativistic black hole. This is purely due to the presence, and coupling to, additional gravitational degrees of freedom.</p> <p>I will also explore the landscape of hairy black hole solutions in the wake of the multi- messenger observation of GW/GRB170817, and show that it is increasingly difficult to endow a black hole with scalar hair in modified gravity given the constraint that gravita- tional waves must propagate at the speed of light.</p> <p>In addition, black hole perturbations in General Relativity are analysed, with analytic expressions for QNM frequencies calculated for scalar, vector, and gravitational perturba- tions to a slowly rotating Kerr-(Anti-)de Sitter black hole.</p> <p>Finally, I will examine the specific case of black hole perturbations in Horndeski the- ory, demonstrating the qualitative difference in gravitational wave emission from a per- turbed black hole in General Relativity and in Horndeski gravity. I will also forecast the detectability of such a modified gravitational wave signal, and estimate what constraints one might be able to place on fundamental parameters of Horndeski gravity through gravi- tational wave observations.</p> |
| first_indexed | 2024-03-06T18:31:38Z |
| format | Thesis |
| id | oxford-uuid:09d7e2d6-d61d-4f1e-a6e0-fbff96b57b16 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-12-09T03:28:22Z |
| publishDate | 2019 |
| record_format | dspace |
| spelling | oxford-uuid:09d7e2d6-d61d-4f1e-a6e0-fbff96b57b162024-12-01T11:10:28ZTesting gravity with black holesThesishttp://purl.org/coar/resource_type/c_db06uuid:09d7e2d6-d61d-4f1e-a6e0-fbff96b57b16AstrophysicsEnglishORA Deposit2019Tattersall, OFerreira, P<p>In this thesis, I study the ways in which modified theories of gravity might be tested for using black holes. In particular, I focus on ways in which the gravitational waves emitted during the ‘ringdown’ of a perturbed black hole may be affected.</p> <p>I will develop and demonstrate the use of a framework for analysing the evolution of perturbations in arbitrary modified gravity theories in both cosmological and black hole backgrounds. I will use this to show that the characteristic Quasi-normal mode (QNM) spectrum of frequencies for the gravitational waves emitted from a perturbed black hole may be altered even in the case that the background black hole is identical to a general relativistic black hole. This is purely due to the presence, and coupling to, additional gravitational degrees of freedom.</p> <p>I will also explore the landscape of hairy black hole solutions in the wake of the multi- messenger observation of GW/GRB170817, and show that it is increasingly difficult to endow a black hole with scalar hair in modified gravity given the constraint that gravita- tional waves must propagate at the speed of light.</p> <p>In addition, black hole perturbations in General Relativity are analysed, with analytic expressions for QNM frequencies calculated for scalar, vector, and gravitational perturba- tions to a slowly rotating Kerr-(Anti-)de Sitter black hole.</p> <p>Finally, I will examine the specific case of black hole perturbations in Horndeski the- ory, demonstrating the qualitative difference in gravitational wave emission from a per- turbed black hole in General Relativity and in Horndeski gravity. I will also forecast the detectability of such a modified gravitational wave signal, and estimate what constraints one might be able to place on fundamental parameters of Horndeski gravity through gravi- tational wave observations.</p> |
| spellingShingle | Astrophysics Tattersall, O Testing gravity with black holes |
| title | Testing gravity with black holes |
| title_full | Testing gravity with black holes |
| title_fullStr | Testing gravity with black holes |
| title_full_unstemmed | Testing gravity with black holes |
| title_short | Testing gravity with black holes |
| title_sort | testing gravity with black holes |
| topic | Astrophysics |
| work_keys_str_mv | AT tattersallo testinggravitywithblackholes |