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Related papers: White Dwarf Critical Tests for Modified Gravity

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Rotating white dwarfs undergoing quasi-radial oscillations can emit gravitational radiation in a frequency range from 0.1 - 0.3 Hz. Assuming that the energy source for the gravitational radiation comes from the oblateness of the white dwarf…

Astrophysics · Physics 2009-11-10 M. Benacquista , D. Sedrakian , M. Hairapetyan , K. Shahabasyan , A. Sadoyan

Twenty years have passed since the discovery of the accelerated expansion of the Universe, reviving the interest for alternative theories of gravity. Adding a scalar degree of freedom to the usual metric of general relativity is one of the…

General Relativity and Quantum Cosmology · Physics 2018-10-11 Antoine Lehébel

The prediction of the spins of the compact remnants is a fundamental goal of the theory of stellar evolution. Here, we confront the predictions for white dwarf spins from evolutionary models including rotation with observational…

Astrophysics · Physics 2009-11-13 M. P. L. Suijs , N. Langer , A. -J. Poelarends , S. -C. Yoon , A. Heger , F. Herwig

Over the last decade or so, we have been developing the possible existence of highly magnetized white dwarfs with analytical stellar structure models. While the primary aim was to explain the nature of the peculiar overluminous type Ia…

High Energy Astrophysical Phenomena · Physics 2021-11-01 B. Mukhopadhyay , M. Bhattacharya , A. J. Hackett , S. Kalita , D. Karinkuzhi , C. A. Tout

This paper gives an overview of the properties of all possible equilibrium sequences of compact strange-matter stars with nuclear crusts, which range from strange stars to strange dwarfs. In contrast to their non-strange counterparts,…

Astrophysics · Physics 2007-05-23 F. Weber , Ch. Schaab , M. K. Weigel , N. K. Glendenning

We study the motion of particles in the background of a scalar-tensor theory of gravity in which the scalar field is kinetically coupled to Einstein tensor. We constrain the value of the derivative parameter $z$ through solar system tests.…

General Relativity and Quantum Cosmology · Physics 2020-12-02 P. A. González , Marco Olivares , Eleftherios Papantonopoulos , Yerko Vásquez

The Chandrasekhar limit for white dwarfs has been confirmed by many astrophysical observations. However, how to obtain it theoretically in models which rely on other-than-Heisenberg's uncertainty principles, which are predicted by some…

General Relativity and Quantum Cosmology · Physics 2023-03-28 Daniele Gregoris , Yen Chin Ong

Wide binary stars are used to test the modified gravity called Scalar-Tensor-Vector Gravity or MOG. This theory is based on the additional gravitational degrees of freedom, the scalar field $G=G_N(1+\alpha)$, where $G_N$ is Newton's…

General Relativity and Quantum Cosmology · Physics 2024-05-31 John W. Moffat

We consider the scalar field profile around relativistic compact objects such as neutron stars for a range of modified gravity models with screening mechanisms of the chameleon and Damour-Polyakov types. We focus primarily on inverse power…

General Relativity and Quantum Cosmology · Physics 2017-04-19 Philippe Brax , Anne-Christine Davis , Rahul Jha

We present results from the high precision timing analysis of the pulsar-white dwarf (WD) binary PSR J1012+5307 using 15 years of multi-telescope data. Observations were performed regularly by the European Pulsar Timing Array (EPTA)…

The shape of the luminosity function of white dwarfs (WDLF) is sensitive to the characteristic cooling time and, therefore, it can be used to test the existence of additional sources or sinks of energy such as those predicted by alternative…

Solar and Stellar Astrophysics · Physics 2020-10-14 Jordi Isern

Modified theories of gravity provide us with a unique opportunity to generate innovative tests of gravity. In Chameleon f(R) gravity, the gravitational potential differs from the weak-field limit of general relativity (GR) in a mass…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-26 Alejo Stark , Christopher J. Miller , Nicholas Kern , Daniel Gifford , Gong-Bo Zhao , Baojiu Li , Kazuya Koyama , Robert C. Nichol

White dwarf atmospheres are subjected to gravitational potentials around $10^5$ times larger than occur on Earth. They provide a unique environment in which to search for any possible variation in fundamental physics in the presence of…

The properties of uniformly rotating white dwarfs are analyzed within the framework of general relativity. Hartle's formalism is applied to construct self-consistently the internal and external solutions to the Einstein equations. The mass,…

Solar and Stellar Astrophysics · Physics 2012-10-29 Kuantay Boshkayev , Jorge Rueda , Remo Ruffini

We calculate the bounds which could be placed on scalar-tensor theories of gravity of the Jordan, Fierz, Brans and Dicke type by measurements of gravitational waveforms from neutron stars (NS) spiralling into massive black holes (MBH) using…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Paul D. Scharre , Clifford M. Will

The magnetic fields of white dwarfs distort their shape generating an anisotropic moment of inertia. A magnetized white dwarf which rotates obliquely relative to the symmetry axis has a mass quadrupole moment which varies in time, so it…

Astrophysics · Physics 2009-10-31 Jeremy S. Heyl

We systematically assess several limiting cases of modified gravity, where particular theoretical or observational conditions hold. This framework includes the well known scalar-tensor gravity and No Slip Gravity and No Run Gravity, and we…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-15 Eric V. Linder

We discuss the feasibility of using astrophysical observations of white dwarfs as probes of fundamental physics. We quantify the effects of varying fundamental couplings on the white dwarf mass-radius relation in a broad class of…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-17 D. M. N. Magano , J. M. A. Vilas Boas , C. J. A. P. Martins

Due to the highly degeneracy of electrons in white dwarf stars, we expect that the relativistic effects play very important role in these stars. In the present article, we study the properties of the condensed matter in white dwarfs using…

Solar and Stellar Astrophysics · Physics 2020-03-24 M. I. Nouh , A. S. Saad , M. M. Elkhateeb , B. Korany

Hot white dwarf stars are the ideal probe for a relationship between the fine-structure constant and strong gravitational fields, providing us with an opportunity for a direct observational test. We study a sample of hot white dwarf stars,…