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Most of low- and intermediate-mass stars that populate the Universe will end their lives as white dwarf stars. These ancient stellar remnants have encrypted inside a precious record of the evolutionary history of the progenitor stars,…

Solar and Stellar Astrophysics · Physics 2014-12-23 A. H. Córsico

In this work, we investigate the equilibrium structure of white dwarfs within the covariant formulation of symmetric teleparallel $f(Q)$ gravity, in which gravity is described by the nonmetricity scalar $Q$ instead of spacetime curvature.…

General Relativity and Quantum Cosmology · Physics 2026-03-24 Rajasmita Sahoo

Observations of several peculiar, under- and over-luminous type Ia supernovae (SNeIa) argue for exploding masses widely different from the Chandrasekhar-limit. We explore the modification to Einstein's gravity in white dwarfs for the first…

High Energy Astrophysical Phenomena · Physics 2016-03-02 Banibrata Mukhopadhyay

In this paper we demonstrate how pulsating white dwarfs can be used as an astrophysical laboratory for empirically constraining convection in these stars. We do this using a technique for fitting observed non-sinusoidal light curves, which…

Astrophysics · Physics 2009-11-13 M. H. Montgomery

Some models (such as the Skyrme model, a low-energy effective field theory for QCD) suggest that the high-density matter prevailing in neutron star interiors may be significantly anisotropic. Anisotropy is known to affect the bulk…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Hector O. Silva , Caio F. B. Macedo , Emanuele Berti , Luís C. B. Crispino

We investigate the luminosity and cooling of highly magnetized white dwarfs where cooling occurs by the diffusion of photons. We solve the magnetostatic equilibrium and photon diffusion equations to obtain the temperature and density…

Solar and Stellar Astrophysics · Physics 2018-10-19 Mukul Bhattacharya , Banibrata Mukhopadhyay , Subroto Mukerjee

Compact stars above a critical stellar mass develop large scalar fields in some scalar-tensor theories. This scenario, called spontaneous scalarization, has been an intense topic of study since it passes weak-field gravity tests naturally…

General Relativity and Quantum Cosmology · Physics 2025-08-07 Kıvanç İ. Ünlütürk , Semih Tuna , Oğuzhan K. Yamak , Fethi M. Ramazanoğlu

To the best of our knowledge, there are no specific calculations of gravity-darkening exponents for white dwarfs in the literature. On the other hand, the number of known eclipsing binaries whose components are tidally and/or rotationally…

Solar and Stellar Astrophysics · Physics 2021-04-28 A. Claret

We study relativistic stars in degenerate higher-order scalar-tensor theories that evade the constraint on the speed of gravitational waves imposed by GW170817. It is shown that the exterior metric is given by the usual Schwarzschild…

General Relativity and Quantum Cosmology · Physics 2018-05-16 Tsutomu Kobayashi , Takashi Hiramatsu

We study the effects of heavy quarks on the equation of state for cold and dense quark matter obtained from perturbative QCD, yielding observables parametrized only by the renormalization scale. We investigate the thermodynamics of charm…

High Energy Physics - Phenomenology · Physics 2020-08-21 José C. Jiménez , Eduardo S. Fraga

White dwarfs are stellar remnants devoid of a nuclear energy source, gradually cooling over billions of years and eventually freezing into a solid state from the inside out. Recently, it was discovered that a population of freezing white…

Solar and Stellar Astrophysics · Physics 2024-09-09 Antoine Bédard , Simon Blouin , Sihao Cheng

The evolution of binaries consisting of evolved main sequence stars (1 < M_d/Msun < 3.5) with white dwarf companions (0.7 < M_wd/Msun < 1.2) is investigated through the thermal mass transfer phase. Taking into account the stabilizing effect…

Astrophysics · Physics 2016-08-30 Natalia Ivanova , Ronald E. Taam

We study the impact of non-local modifications of General Relativity on stellar structure. In particular, assuming an analytic distortion function and specific equations of state, we made use of remnant stars to put qualitative constraints…

General Relativity and Quantum Cosmology · Physics 2023-01-23 Grigoris Panotopoulos , Javier Rubio , Ilídio Lopes

We present the first radiation magnetohydrodynamics simulations of the atmosphere of white dwarf stars. We demonstrate that convective energy transfer is seriously impeded by magnetic fields when the plasma-beta parameter, the thermal to…

Solar and Stellar Astrophysics · Physics 2015-10-14 P. -E. Tremblay , G. Fontaine , B. Freytag , O. Steiner , H. -G. Ludwig , M. Steffen , S. Wedemeyer , P. Brassard

Many white dwarfs have accreted material from their own planetary systems. These objects can be used to infer the composition of exoplanetary material and identify evidence for key geological processes. However, the white dwarf atmospheric…

Earth and Planetary Astrophysics · Physics 2025-10-22 Andrew M. Buchan , Pier-Emmanuel Tremblay , Antoine Bédard , Evan B. Bauer , Tim Cunningham

More than 40 years have passed since Ed Salpeter and others predicted that the carbon/oxygen cores of the coolest white dwarf stars in our Galaxy will theoretically crystallize. This effect has a dramatic impact on the calculated ages of…

Astrophysics · Physics 2007-05-23 T. S. Metcalfe , M. H. Montgomery , A. Kanaan

We study phenomenological features and stability of boson stars in massless and massive scalar-tensor theory of gravity with Damour-Esposito-Farese coupling. This coupling between the tensor and scalar sectors of the theory leads to a…

General Relativity and Quantum Cosmology · Physics 2024-07-29 Tamara Evstafyeva , Roxana Rosca-Mead , Ulrich Sperhake , Bernd Brugmann

A subset of blazars emit TeV gamma rays which annihilate and pair produce on the extragalactic background light. We have argued in Broderick et al. (2011, Paper I) that plasma beam instabilities can dissipate the pairs' energy locally. This…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Christoph Pfrommer , Philip Chang , Avery E. Broderick

The explosion of a type Ia supernova starts in a white dwarf as a laminar deflagration at the center of the star and soon several hydrodynamic instabilities, in particular, the Rayleigh-Taylor instability, begin to act. A cellular…

An ungravity-inspired model is employed to examine the astrophysical parameters of white dwarf stars (WDs) using polytropic and degenerate gas approaches. Based on the observed properties such as mass, radius, and luminosity of selected…

Solar and Stellar Astrophysics · Physics 2016-06-06 Orfeu Bertolami , Hodjat Mariji