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Related papers: White Dwarf Structure in $f(Q)$ Gravity

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A population of anomalous ultra-massive white dwarfs discovered with Gaia, often referred to as the Q branch, show high (multi-Gyr) cooling delays produced by exotic physical mechanisms. They are believed to be the products of stellar…

Around 10% of white dwarfs exhibit global magnetic structures with fields ranging from 1 kG to hundreds of MG. Recently, the first radiation magnetohydrodynamics simulations of the atmosphere of white dwarfs showed that convection should be…

Recent literature has seen an ongoing discussion on the limiting mass of strongly magnetized white dwarfs, since such objects may prove to be a source of over-luminous type-Ia supernovae. In an earlier paper, we have presented the…

Solar and Stellar Astrophysics · Physics 2016-01-20 Prasanta Bera , Dipankar Bhattacharya

In recent years a number of white dwarfs has been observed with very high surface magnetic fields. We can expect that the magnetic field in the core of these stars would be much higher (~ 10^{14} G). In this paper, we analytically study the…

Solar and Stellar Astrophysics · Physics 2012-05-09 Aritra Kundu , Banibrata Mukhopadhyay

The main objective of this article is to study the viable compact stellar structures in non-Riemannian geometry, i.e., $f(\mathbb{Q},T)$ theory, where $\mathbb{Q}$ defines the non-metricity and $T$ represents trace of the stress-energy…

General Relativity and Quantum Cosmology · Physics 2024-04-02 M. Zeeshan Gul , M. Sharif , Adeeba Arooj

We present the first detailed 3D kinematic analysis of a sample of 3133 white dwarfs that use Gaia astrometry plus radial velocities, which were measured either by Gaia or by ground based spectroscopic observations. The sample includes…

In this work, we investigate neutron stars (NSs) in the strong field regime within the framework of symmetric teleparallel $f(Q)$ gravity, considering three representative models: linear, logarithmic, and exponential. While Bayesian studies…

General Relativity and Quantum Cosmology · Physics 2026-02-19 Sneha Pradhan , N. K. Patra , Kai Zhou , P. K. Sahoo

We investigate the properties of anisotropic white dwarf stars within the rainbow gravity adopting for matter content the Chandrasekhar model based on an ideal Fermi gas at zero temperature. We study in detail the effects of the anisotropic…

General Relativity and Quantum Cosmology · Physics 2024-11-20 Takol Tangphati , Grigoris Panotopoulos , Ayan Banerjee , Anirudh Pradhan

White dwarf photospheric parameters are usually obtained by means of spectroscopic or photometric analysis. These results are not always consistent with each other, with the published values often including just the statistical…

In this study, we present a novel approach to mimetic gravity incorporating a non-zero nonmetricity tensor with vanishing torsion and curvature, establishing a generalized mimetic-$f(Q)$ gravity framework. Using the Lagrange multiplier…

General Relativity and Quantum Cosmology · Physics 2024-09-20 Adam Z. Kaczmarek

In this paper, we investigate the homogeneous and isotropic flat FLRW Universe in the logarithmic form of $f\left( Q\right) $ gravity, where $% Q $ is the non-metricity scalar, specifically, $f\left( Q\right) =\alpha +\beta \log \left(…

General Relativity and Quantum Cosmology · Physics 2022-08-30 M. Koussour , S. H. Shekh , A. Hanin , Z. Sakhi , S. R. Bhoyer , M. Bennai

The hydrogen envelope is the outermost layer of a DA white dwarf; it makes up the entirety of the stellar photosphere, and yet its typical extent is difficult to model theoretically and remains poorly observationally constrained. As a…

Solar and Stellar Astrophysics · Physics 2026-03-05 Stefan M. Arseneau , J. J. Hermes , Maria E. Camisassa , Roberto Raddi , Evan B. Bauer

This paper describes a revised photometric calibration of the \emph{Galaxy Evolution Explorer} magnitudes, based on measurements of DA white dwarfs. The photometric magnitudes of white dwarfs measured by \emph{GALEX} are compared to…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 L Camarota , J B Holberg

We study spherically symmetric configurations of the quadratic $f(R)$ gravity in the Einstein frame. In case of a purely gravitational system, we have determined the global qualitative behavior of the metric and the scalaron field for all…

General Relativity and Quantum Cosmology · Physics 2024-07-30 V. I. Zhdanov , O. S. Stashko , Yu. V. Shtanov

We formulate $f(Q,C)$ gravity and cosmology. Such a construction is based on the symmetric teleparallel geometry, but apart form the non-metricity scalar $Q$ we incorporate in the Lagrangian the boundary term $C$ of its difference form the…

General Relativity and Quantum Cosmology · Physics 2024-04-09 Avik De , Tee-How Loo , Emmanuel N. Saridakis

White dwarfs which exhibit transit signatures of planetary debris and accreted planetary material provide exceptional opportunities to probe the material composition and dynamical structure of planetary systems. Although previous…

Earth and Planetary Astrophysics · Physics 2021-07-14 Catriona H. McDonald , Dimitri Veras

We investigate isolated sub- and super-Chandrasekhar white dwarfs which lose angular momentum through magnetic dipole braking. We construct constant rest mass sequences by fulfilling all stability criteria of rotating configurations and…

Solar and Stellar Astrophysics · Physics 2016-04-11 Kuantay Boshkayev , Jorge A. Rueda , Remo Ruffini , Bakytzhan Zhami

Recent advances in nuclear theory combined with new astrophysical observations have led to the need for specific theoretical models that actually apply to phenomena on dense-matter physics. At the same time, quantum chromodynamics (QCD)…

General Relativity and Quantum Cosmology · Physics 2022-08-30 Juan M. Z. Pretel , Takol Tangphati , Ayan Banerjee , Anirudh Pradhan

In November 2019, the nearby single, isolated DQ-type white dwarf LAWD 37 (WD 1142-645) aligned closely with a distant background source and caused an astrometric microlensing event. Leveraging astrometry from \Gaia{} and followup data from…

The effects implied for the structure of compact objects by the modification of General Relativity produced by the generalization of the Lagrangian density to the form f(R)=R+\alpha R^2, where R is the Ricci curvature scalar, have been…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-24 Mariana Orellana , Federico García , Florencia Anabella Teppa Pannia , Gustavo Esteban Romero