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arXiv · 1410.6265

Marginally stable circular orbit of a test body in spherically symmetric and static spacetimes

Toshiaki Ono·Tomohito Suzuki·Naomasa Fushimi·Kei Yamada·Hideki Asada
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Abstract

We study a marginally stable circular orbit (MSCO) such as the innermost stable circular orbit (ISCO) of a timelike geodesic in any spherically symmetric and static spacetime. It turns out that the metric components are separable from the constants of motion along geodesics. We show also that a metric component $g_{rr}$ with a radial coordinate $r$ does not affect MSCOs. This suggests that, as a test of gravity, any ISCO measurement may be put into the same category as gravitational redshift experiments. MSCOs for exact solutions to the Einstein's equation are also mentioned.

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Toshiaki Ono, Tomohito Suzuki, Naomasa Fushimi, Kei Yamada, Hideki Asada. 2014-10-23. Marginally stable circular orbit of a test body in spherically symmetric and static spacetimes. https://arxiv.org/abs/1410.6265

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