Gravitational radiation of a spherically symmetric source in f(R)-gravitation

Abstract It is shown that Birkhoff’s theorem for the general theory of relativity is overcome in the f(R)-theory of gravitation. That means, the f(R)-theory of gravitation, unlike Einstein’s general theory of relativity, does not forbid gravitational radiation from a spherically symmetric source (wh...

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Main Authors: Pham Van Ky, Nguyen Thi Hong Van, Nguyen Anh Ky
Format: Article
Language:English
Published: SpringerOpen 2024-03-01
Series:European Physical Journal C: Particles and Fields
Online Access:https://doi.org/10.1140/epjc/s10052-024-12606-y
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author Pham Van Ky
Nguyen Thi Hong Van
Nguyen Anh Ky
author_facet Pham Van Ky
Nguyen Thi Hong Van
Nguyen Anh Ky
author_sort Pham Van Ky
collection DOAJ
description Abstract It is shown that Birkhoff’s theorem for the general theory of relativity is overcome in the f(R)-theory of gravitation. That means, the f(R)-theory of gravitation, unlike Einstein’s general theory of relativity, does not forbid gravitational radiation from a spherically symmetric source (whether stationary or non-stationary). As a consequence, in the f(R)-theory a spherically symmetric gravitational deformation (e.g., collapse/expansion or pulsation) could emit gravitational waves (of tensor- and scalar polarization modes), a phenomenon impossible in the general relativity. A test model is examined and it turns out that the gravitational radiation is strongest when the surface of the deforming object is in the vicinity of the (modified) event horizon, even suddenly flares up just outside the latter. In this letter, within the f(R)-theory of gravitation, a gravitational wave equation and a formula for the gravitational emission power are derived. These formulae, along with searching for signals, can be used for the experimental test of the f(R)-theory. In general, including the spherically symmetry case, gravitational radiation of both tensor- and scalar polarization modes are allowed, although under some circumstance the contribution of scalar modes is strongly suppressed.
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spelling doaj.art-9208cf0d60254df1bc5799076b82c4fc2024-03-24T12:31:21ZengSpringerOpenEuropean Physical Journal C: Particles and Fields1434-60522024-03-018431910.1140/epjc/s10052-024-12606-yGravitational radiation of a spherically symmetric source in f(R)-gravitationPham Van Ky0Nguyen Thi Hong Van1Nguyen Anh Ky2Mathematical-, High Energy- and Astro-Physics Group, CTP, Institute of Physics, Vietnam Academy of Science and Technology (VAST)Mathematical-, High Energy- and Astro-Physics Group, CTP, Institute of Physics, Vietnam Academy of Science and Technology (VAST)Mathematical-, High Energy- and Astro-Physics Group, CTP, Institute of Physics, Vietnam Academy of Science and Technology (VAST)Abstract It is shown that Birkhoff’s theorem for the general theory of relativity is overcome in the f(R)-theory of gravitation. That means, the f(R)-theory of gravitation, unlike Einstein’s general theory of relativity, does not forbid gravitational radiation from a spherically symmetric source (whether stationary or non-stationary). As a consequence, in the f(R)-theory a spherically symmetric gravitational deformation (e.g., collapse/expansion or pulsation) could emit gravitational waves (of tensor- and scalar polarization modes), a phenomenon impossible in the general relativity. A test model is examined and it turns out that the gravitational radiation is strongest when the surface of the deforming object is in the vicinity of the (modified) event horizon, even suddenly flares up just outside the latter. In this letter, within the f(R)-theory of gravitation, a gravitational wave equation and a formula for the gravitational emission power are derived. These formulae, along with searching for signals, can be used for the experimental test of the f(R)-theory. In general, including the spherically symmetry case, gravitational radiation of both tensor- and scalar polarization modes are allowed, although under some circumstance the contribution of scalar modes is strongly suppressed.https://doi.org/10.1140/epjc/s10052-024-12606-y
spellingShingle Pham Van Ky
Nguyen Thi Hong Van
Nguyen Anh Ky
Gravitational radiation of a spherically symmetric source in f(R)-gravitation
European Physical Journal C: Particles and Fields
title Gravitational radiation of a spherically symmetric source in f(R)-gravitation
title_full Gravitational radiation of a spherically symmetric source in f(R)-gravitation
title_fullStr Gravitational radiation of a spherically symmetric source in f(R)-gravitation
title_full_unstemmed Gravitational radiation of a spherically symmetric source in f(R)-gravitation
title_short Gravitational radiation of a spherically symmetric source in f(R)-gravitation
title_sort gravitational radiation of a spherically symmetric source in f r gravitation
url https://doi.org/10.1140/epjc/s10052-024-12606-y
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