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The properties of uniformly rotating white dwarfs (RWDs) are analyzed within the framework of general relativity. Hartle's formalism is applied to construct the internal and external solutions to the Einstein equations. The WD matter is…

Solar and Stellar Astrophysics · Physics 2015-03-20 Kuantay Boshkayev , Jorge A. Rueda , Remo Ruffini , Ivan Siutsou

In the context of $f\left(R, T\right) = R + 2 \beta T$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of the energy-momentum tensor, the equilibrium structure of charged anisotropic white dwarfs (WDs) is studied. The stellar…

General Relativity and Quantum Cosmology · Physics 2025-03-25 Zhe Feng

White dwarfs are compact objects that stand against gravitational collapse by their internal pressure of degenerate matter. In this work we aimed to perform an introductory study on these stars, using two equations of state (EOS): (I) an…

Solar and Stellar Astrophysics · Physics 2018-06-22 Sílvia Pereira Nunes , Marcelo Chiapparini , Santiago Esteban Perez Bergliaffa

We make use of the high photometric precision of Kepler to search for periodic modulations among 14 normal (DA- and DB-type, likely non-magnetic) hot white dwarfs (WDs). In five, and possibly up to seven of the WDs, we detect periodic, ~2…

Solar and Stellar Astrophysics · Physics 2015-06-22 Dan Maoz , Tsevi Mazeh , Amy McQuillan

In this article we study the hydrostatic equilibrium configuration of neutron stars (NSs) and strange stars (SSs), whose fluid pressure is computed from the equations of state $p=\omega\rho^{5/3}$ and $p=0.28(\rho-4{\cal B})$, respectively,…

General Relativity and Quantum Cosmology · Physics 2018-08-17 P. H. R. S. Moraes , J. D. V. Arbañil , G. A. Carvalho , R. V. Lobato , E. Otoniel , R. M. Marinho , M. Malheiro

We suggest that white dwarf (WD) pulsars can compete with neutron star (NS) pulsars for producing the excesses of cosmic ray electrons/positrons observed by the PAMELA, ATIC/PPB-BETS, Fermi and HESS experiments. A merger of two WDs leads to…

High Energy Astrophysical Phenomena · Physics 2015-04-23 Kazumi Kashiyama , Kunihito Ioka , Norita Kawanaka

There has been a growing interest within the astrophysics community in highly magnetized and fast-spinning white dwarfs (WDs), commonly referred to as HMWDs. WDs with these characteristics are quite uncommon and possess magnetic fields…

Solar and Stellar Astrophysics · Physics 2024-12-20 M. F. Sousa , E. Otoniel , J. G. Coelho , J. C. N. de Araujo

We examine the potential of asteroseismology for exploring the internal rotation of white dwarf stars. Data from global observing campaigns have revealed a wealth of frequencies, some of which show the signature of rotational splitting.…

Astrophysics · Physics 2009-10-31 Steven D. Kawaler , Takashi Sekii , Douglas Gough

We use the most recent, complete and independent measurements of masses and radii of white dwarfs in binaries to bound the class of non-trivial modified gravity theories, viable after GW170817/GRB170817, using its effect on the mass-radius…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Ippocratis D. Saltas , Ignacy Sawicki , Ilidio Lopes

A number of White Dwarfs (WDs) in cataclysmic binaries have shown brightness variations consistent with non-radial oscillations as observed in isolated WDs. A few objects have been well-characterized with photometric campaigns in the hopes…

Solar and Stellar Astrophysics · Physics 2016-01-12 Dean M. Townsley , Phil Arras , Lars Bildsten

We explore the internal structures of the white dwarfs in two different modified theories of gravity: (i) scalar-tensor-vector gravity and (ii) beyond Horndeski theories of $G_3$ type. The modification of the gravitational force inside the…

General Relativity and Quantum Cosmology · Physics 2023-01-31 Khursid Alam , Tousif Islam

In this paper, we focus on the effect of mass-transfer between compact binaries like neutron-star-neutron-star (NS-NS) systems and neutron-star-white-dwarf (NS-WD) systems on gravitational waves (GWs). We adopt the mass quadrupole formula…

General Relativity and Quantum Cosmology · Physics 2024-03-14 Zi-han Zhang , Bin Liu , Sheng-hua Yu , Jie Yang

In the past decades, several neutron stars (NSs), particularly pulsars, with mass $M>2M_\odot$ have been observed. On the other hand, the existence of massive white dwarfs (WDs), even violating Chandrasekhar mass-limit, was inferred from…

High Energy Astrophysical Phenomena · Physics 2025-09-10 Mayusree Das , Banibrata Mukhopadhyay

White dwarfs (WDs) are the final fate of about 97\% of the stars in our galaxy, making them vital tracers of stellar history. A fraction of WDs exist in cataclysmic variable (CV) systems, accreting matter from a nearby companion star. A…

Solar and Stellar Astrophysics · Physics 2026-03-02 Praphull Kumar , Dean M. Townsley , Hunter Anz

At present, a large number of pulsating white dwarf (WD) stars is being discovered either from Earth-based surveys such as the Sloan Digital Sky Survey, or through observations from space (e.g., the Kepler mission). The asteroseismological…

Solar and Stellar Astrophysics · Physics 2017-03-06 Alejandro H. Córsico

Generic scalar-tensor theories of gravity predict deviations from Newtonian physics inside astrophysical bodies. In this paper, we point out that low mass stellar objects, red and brown dwarf stars, are excellent probes of these theories.…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-12 Jeremy Sakstein

The mass-radius relations for white dwarf stars are investigated by solving the Newtonian as well as Tolman-Oppenheimer-Volkoff (TOV) equations for hydrostatic equilibrium assuming the electron gas to be non-interacting. We find that the…

Solar and Stellar Astrophysics · Physics 2017-11-07 Arun Mathew , Malay K. Nandy

The standard numerical tools for studying non-linear collapse of matter are Newtonian $N$-body simulations. Previous work has shown that these simulations are in accordance with General Relativity (GR) up to first order in perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-07 Christian Fidler , Thomas Tram , Cornelius Rampf , Robert Crittenden , Kazuya Koyama , David Wands

White dwarf-neutron star binaries generate detectable gravitational radiation. We construct Newtonian equilibrium models of corotational white dwarf-neutron star (WDNS) binaries in circular orbit and find that these models terminate at the…

High Energy Astrophysical Phenomena · Physics 2010-04-22 Vasileios Paschalidis , Morgan MacLeod , Thomas W. Baumgarte , Stuart L. Shapiro

In this work we investigate the equilibrium configurations of white dwarfs in a modified gravity theory, na\-mely, $f(R,T)$ gravity, for which $R$ and $T$ stand for the Ricci scalar and trace of the energy-momentum tensor, respectively.…

General Relativity and Quantum Cosmology · Physics 2017-12-20 G. A. Carvalho , R. V. Lobato , P. H. R. S. Moraes , José D. V. Arbañil , R. M. Marinho , E. Otoniel , M. Malheiro