Spacetime and orbits of bumpy black holes
Our Universe contains a great number of extremely compact and massive objects which are generally accepted to be black holes. Precise observations of orbital motion near candidate black holes have the potential to determine if they have the spacetime structure that general relativity demands. As a m...
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| Format: | Article |
| Language: | en_US |
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American Physical Society
2010
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| Online Access: | http://hdl.handle.net/1721.1/58786 https://orcid.org/0000-0001-6211-1388 |
| _version_ | 1811069023255789568 |
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| author | Vigeland, Sarah Jane Hughes, Scott A |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Vigeland, Sarah Jane Hughes, Scott A |
| author_sort | Vigeland, Sarah Jane |
| collection | MIT |
| description | Our Universe contains a great number of extremely compact and massive objects which are generally accepted to be black holes. Precise observations of orbital motion near candidate black holes have the potential to determine if they have the spacetime structure that general relativity demands. As a means of formulating measurements to test the black hole nature of these objects, Collins and Hughes introduced “bumpy black holes”: objects that are almost, but not quite, general relativity’s black holes. The spacetimes of these objects have multipoles that deviate slightly from the black hole solution, reducing to black holes when the deviation is zero. In this paper, we extend this work in two ways. First, we show how to introduce bumps which are smoother and lead to better behaved orbits than those in the original presentation. Second, we show how to make bumpy Kerr black holes—objects which reduce to the Kerr solution when the deviation goes to zero. This greatly extends the astrophysical applicability of bumpy black holes. Using Hamilton-Jacobi techniques, we show how a spacetime’s bumps are imprinted on orbital frequencies, and thus can be determined by measurements which coherently track the orbital phase of a small orbiting body. We find that in the weak field, orbits of bumpy black holes are modified exactly as expected from a Newtonian analysis of a body with a prescribed multipolar structure, reproducing well-known results from the celestial mechanics literature. The impact of bumps on strong-field orbits is many times greater than would be predicted from a Newtonian analysis, suggesting that this framework will allow observations to set robust limits on the extent to which a spacetime’s multipoles deviate from the black hole expectation. |
| first_indexed | 2024-09-23T08:04:28Z |
| format | Article |
| id | mit-1721.1/58786 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T08:04:28Z |
| publishDate | 2010 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/587862022-09-30T07:17:59Z Spacetime and orbits of bumpy black holes Vigeland, Sarah Jane Hughes, Scott A Massachusetts Institute of Technology. Department of Physics MIT Kavli Institute for Astrophysics and Space Research Hughes, Scott A. Vigeland, Sarah Jane Hughes, Scott A. Our Universe contains a great number of extremely compact and massive objects which are generally accepted to be black holes. Precise observations of orbital motion near candidate black holes have the potential to determine if they have the spacetime structure that general relativity demands. As a means of formulating measurements to test the black hole nature of these objects, Collins and Hughes introduced “bumpy black holes”: objects that are almost, but not quite, general relativity’s black holes. The spacetimes of these objects have multipoles that deviate slightly from the black hole solution, reducing to black holes when the deviation is zero. In this paper, we extend this work in two ways. First, we show how to introduce bumps which are smoother and lead to better behaved orbits than those in the original presentation. Second, we show how to make bumpy Kerr black holes—objects which reduce to the Kerr solution when the deviation goes to zero. This greatly extends the astrophysical applicability of bumpy black holes. Using Hamilton-Jacobi techniques, we show how a spacetime’s bumps are imprinted on orbital frequencies, and thus can be determined by measurements which coherently track the orbital phase of a small orbiting body. We find that in the weak field, orbits of bumpy black holes are modified exactly as expected from a Newtonian analysis of a body with a prescribed multipolar structure, reproducing well-known results from the celestial mechanics literature. The impact of bumps on strong-field orbits is many times greater than would be predicted from a Newtonian analysis, suggesting that this framework will allow observations to set robust limits on the extent to which a spacetime’s multipoles deviate from the black hole expectation. National Science Foundation (U.S.) (No. PHY- 0449884) United States. National Aeronautics and Space Administration (Grant No. NNG05G105G) United States. National Aeronautics and Space Administration (Grant No. NNX08AL42G) 2010-09-30T15:31:15Z 2010-09-30T15:31:15Z 2010-01 2009-11 Article http://purl.org/eprint/type/JournalArticle 1550-7998 1550-2368 http://hdl.handle.net/1721.1/58786 Vigeland, Sarah J. and Scott A. Hughes. "Spacetime and orbits of bumpy black holes." Physical Review D 81.2 (2010): 024030. © 2010 The American Physical Society https://orcid.org/0000-0001-6211-1388 en_US http://dx.doi.org/10.1103/PhysRevD.81.024030 Physical Review D Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Physical Society APS |
| spellingShingle | Vigeland, Sarah Jane Hughes, Scott A Spacetime and orbits of bumpy black holes |
| title | Spacetime and orbits of bumpy black holes |
| title_full | Spacetime and orbits of bumpy black holes |
| title_fullStr | Spacetime and orbits of bumpy black holes |
| title_full_unstemmed | Spacetime and orbits of bumpy black holes |
| title_short | Spacetime and orbits of bumpy black holes |
| title_sort | spacetime and orbits of bumpy black holes |
| url | http://hdl.handle.net/1721.1/58786 https://orcid.org/0000-0001-6211-1388 |
| work_keys_str_mv | AT vigelandsarahjane spacetimeandorbitsofbumpyblackholes AT hughesscotta spacetimeandorbitsofbumpyblackholes |