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Related papers: Vainshtein screening for slowly rotating stars

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This paper is concerned with theories of gravity that contain a scalar coupled both conformally and disformally to matter through the metric. By systematically deriving the non-relativistic limit, it is shown that no new non-linear…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-10 Jeremy Sakstein

We investigate the electromagnetic fields in the vacuum exterior of a rotating relativistic star endowed with a magnetic dipole moment, and with the stellar surface behaving as a perfect conductor. While the stellar rotation is treated in…

Astrophysics · Physics 2009-11-10 Yasufumi Kojima , Norihito Matsunaga , Taishi Okita

We explored the motion of test particles near slowly rotating relativistic star having a uniform luminosity. In order to derive the test particle's equations of motion, we made use of the radiation stress-energy tensor first constructed by…

High Energy Astrophysical Phenomena · Physics 2010-04-14 Jae-Sok Oh , Hongsu Kim , Hyung Mok Lee

Theories of modified gravity, in both the linear and fully non-linear regime, are often studied under the assumption that the evolution of the new (often scalar) degree of freedom present in the theory is quasi-static. This approximation…

General Relativity and Quantum Cosmology · Physics 2015-09-09 Hans A. Winther , Pedro G. Ferreira

We study in detail static spherically symmetric solutions of non linear Pauli-Fierz theory. We obtain a numerical solution with a constant density source. This solution shows a recovery of the corresponding solution of General Relativity…

General Relativity and Quantum Cosmology · Physics 2010-11-11 E. Babichev , C. Deffayet , R. Ziour

We present analytic solutions of Maxwell equations in the internal and external background spacetime of a slowly rotating magnetized neutron star. The star is considered isolated and in vacuum, with a dipolar magnetic field not aligned with…

Astrophysics · Physics 2009-10-31 L. Rezzolla , B. J. Ahmedov , J. C. Miller

In this paper, analytical solutions describing static and spherically symmetric sources in the decoupling limit of massive gravity are derived. We analyze the model parameter range and specify when a Vainshtein mechanism is possible.…

General Relativity and Quantum Cosmology · Physics 2011-11-28 Stefan Sjors , Edvard Mortsell

We study relativistic stars in the context of scalar tensor theories of gravity that try to account for the observed cosmic acceleration and satisfy the local gravity constraints via the chameleon mechanism. More specifically, we consider…

General Relativity and Quantum Cosmology · Physics 2015-03-13 E. Babichev , D. Langlois

Based on the Mathisson-Papapetrou-Dixon (MPD) equations and the Vaidya metric, the motion of a spinning point particle orbiting a non-rotating star while undergoing radiation-induced gravitational collapse is studied in detail. A…

General Relativity and Quantum Cosmology · Physics 2011-07-19 Dinesh Singh

While the geodesic motion around a Kerr black hole is fully integrable and therefore regular, numerical explorations of the phase-space around other spacetime configurations, with a different multipolar structure, have displayed chaotic…

General Relativity and Quantum Cosmology · Physics 2021-05-12 Andrés F. Gutiérrez-Ruiz , Alejandro Cárdenas-Avendaño , Nicolás Yunes , Leonardo A. Pachón

The class of Galileon scalar fields theories encapsulate the Vainshtein screening mechanism which is characteristic of a large range of infrared modified theories of gravity. Such theories can lead to testable departures from General…

High Energy Physics - Theory · Physics 2024-02-09 Claudia de Rham , John T. Giblin , Andrew J. Tolley

We derive the exact frame-dragging rate inside rotating neutron stars. This formula is applied to show that the frame-dragging rate monotonically decreases from the centre to the surface of the neutron star along the pole. In case of…

High Energy Astrophysical Phenomena · Physics 2014-06-27 Chandrachur Chakraborty , Kamakshya Prasad Modak , Debades Bandyopadhyay

In massive gravity, galileon, and braneworld explanations of cosmic acceleration, force modifications are screened by nonlinear derivative self-interactions of the scalar field mediating that force. Interactions between the field of a…

High Energy Physics - Theory · Physics 2013-04-03 Takashi Hiramatsu , Wayne Hu , Kazuya Koyama , Fabian Schmidt

The analysis of axisymmetric spacetimes, dynamical or stationary, is usually made in the reduced space. We prove here a stability property of the quo- tient space and use it together with minimal surface techniques to constraint the shape…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Martin Reiris

The Horndeski theory of gravity is known as the most general scalar-tensor theory with second-order field equations. Recently, it was demonstrated by Gleyzes et al. that the Horndeski theory can further be generalized in such a way that…

General Relativity and Quantum Cosmology · Physics 2015-03-13 Tsutomu Kobayashi , Yuki Watanabe , Daisuke Yamauchi

The axial mode oscillations are examined for relativistic rotating stars with uniform angular velocity. Using the slow rotation formalism and the Cowling approximation, we have derived the equations governing the r-mode oscillations up to…

Astrophysics · Physics 2015-06-24 Yasufumi Kojima , Masayasu Hosonuma

Screening mechanisms allow light scalar fields to dynamically avoid the constraints that come from our lack of observation of a long-range fifth force. Galactic scale tests are of particular interest when the light scalar is introduced to…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-01 Clare Burrage , Bradley March , Aneesh P. Naik

We construct the solutions of slowly rotating gravastars with a thin shell. In the zero-rotation limit, we consider the gravastar composed of a de Sitter core, a thin shell, and Schwarzschild exterior spacetime. The rotational effects are…

General Relativity and Quantum Cosmology · Physics 2016-01-13 Nami Uchikata , Shijun Yoshida

Simple spherical, non-rotating stellar models are inadequate when describing real stars in the limit of very fast rotation: Both the observable spectrum and the geometrical shape of the star deviate strongly from simple models. We attempt…

Solar and Stellar Astrophysics · Physics 2015-05-30 T. H. Dall , L. Sbordone

New fifth forces have not yet been detected in the laboratory or in the solar system, hence it is typically difficult to introduce new light scalar fields that would mediate such forces. In recent years it has been shown that a number of…

High Energy Physics - Theory · Physics 2015-06-11 Philippe Brax , Clare Burrage , Anne-Christine Davis