MG15 - Talk detail |
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Participant |
Archibald, Anne | |||||||
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Institution |
Anton Pannekoek Institute - P.O. Box 94249 - Amsterdam - Noord-Holland - Netherland | |||||||
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Session |
NS4 |
Accepted |
Yes |
Order |
1 |
Time |
15:15 | 30' |
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Talk |
Oral abstract |
Title |
A Pulsar in a Stellar Triple System shows the Universality of Free Fall | |||||
| Coauthors | Gusinskaia, Nina V.; Hessels, Jason W. T.; Deller, Adam W. T.; Kaplan, David L.; Lorimer, Duncan R.; Lynch, Ryan S.; Ransom, Scott M.; Stairs, Ingrid H. | |||||||
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Abstract |
Einstein's theoroy of gravity, general relativity (GR), is based on the universality of free fall: all objects fall the same way in an external gravitational field. In contrast to almost all alternative theories, the strong equivalence principle (SEP) of GR requires this to apply even to bodies with strong self-gravity in spite of the nonlinearity of gravity in post-Newtonian theories. The system PSR J0337+1715 consists of a millisecond radio pulsar in a 1.6-day orbit with an inner white dwarf, and the pair is in a 327-day orbit with an outer white dwarf companion. This allows us to compare the accelerations experienced by the pulsar, which has strong self-gravity, and by the inner white dwarf, as they fall in the gravity of the outer white dwarf. We find the accelerations are consistent, and place a stringent limit on possible differences. The strong gravity of our test body implies tight constraints on gravitational theory, improving on all existing limits. I will talk about the result and its implications for theories of gravity and for gravitational-wave searches with advanced LIGO, the Cosmic Explorer, and the Einstein Telescope. |
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Pdf file |
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