Birkhoff's theorem (relativity)
General relativity |
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In
The theorem was proven in 1923 by George David Birkhoff (author of another famous Birkhoff theorem, the pointwise ergodic theorem which lies at the foundation of ergodic theory). In 2005, Nils Voje Johansen, Finn Ravndal, Stanley Deser[citation needed] stated that the theorem was allegedly published two years earlier by a little-known Norwegian physicist, Jørg Tofte Jebsen.[5][6][non-primary source needed][original research?]
Intuitive rationale
The intuitive idea of Birkhoff's theorem is that a spherically symmetric gravitational field should be produced by some massive object at the origin; if there were another concentration of
Implications
The conclusion that the exterior field must also be stationary is more surprising, and has an interesting consequence. Suppose we have a spherically symmetric star of fixed mass which is experiencing spherical pulsations. Then Birkhoff's theorem says that the exterior geometry must be Schwarzschild; the only effect of the pulsation is to change the location of the
Generalizations
Birkhoff's theorem can be generalized: any spherically symmetric and asymptotically flat solution of the
See also
- Birkhoff's theorem (electromagnetism)
- Newman–Janis algorithm, a complexification technique for finding exact solutions to the Einstein field equations
- Shell theorem in Newtonian gravity
- Quadrupole formula
References
- – via American Physical Society.
- ISBN 978-94-007-5409-6.
- ISBN 0-521-46783-7.
- ISSN 0075-8450.
- ^ J.T. Jebsen, Über die allgemeinen kugelsymmetrischen Lösungen der Einsteinschen Gravitationsgleichungen im Vakuum, Arkiv för matematik, astronomi och fysik, 15 (18), 1 - 9 (1921).
- ^ J.T. Jebsen, On the general symmetric solutions of Einstein's gravitational equations in vacuo, General Relativity and Cosmology 37 (12), 2253 - 2259 (2005).
- S2CID 116755736.
- Deser, S & Franklin, J (2005). "Schwarzschild and Birkhoff a la Weyl". American Journal of Physics. 73 (3): 261–264. S2CID 119454232.
- D'Inverno, Ray (1992). Introducing Einstein's Relativity. Oxford: ISBN 0-19-859686-3. See section 14.6 for a proof of the Birkhoff theorem, and see section 18.1 for the generalized Birkhoff theorem.
- Birkhoff, G. D. (1923). Relativity and Modern Physics. Cambridge, Massachusetts: LCCN 23008297.
- Jebsen, J. T. (1921). "Über die allgemeinen kugelsymmetrischen Lösungen der Einsteinschen Gravitationsgleichungen im Vakuum (On the General Spherically Symmetric Solutions of Einstein's Gravitational Equations in Vacuo)". Arkiv för Matematik, Astronomi och Fysik. 15: 1–9.
External links
- Birkhoff's Theorem on ScienceWorld