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Related papers: Stability criterion for white dwarfs in Palatini $…

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Various experiments and observations have led researchers to suggest different bounds on fundamental constants like the fine-structure constant and the proton-to-electron mass ratio. These bounds differ mostly due to the energy scale of the…

General Relativity and Quantum Cosmology · Physics 2023-06-05 Surajit Kalita , Akhil Uniyal

The evolution of linear cosmological perturbations in modified theories of gravity is investigated assuming the Palatini formalism. It has been discussed about the stability problem in this model based on the equivalence between f(R)…

General Relativity and Quantum Cosmology · Physics 2008-06-18 Seokcheon Lee

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

We consider a particular effect which can be expected in scenarios of deviations from Special Relativity induced by Planckian physics: the loss of additivity in the total energy of a system of particles. We argue about the necessity to…

General Relativity and Quantum Cosmology · Physics 2015-06-17 J. M. Carmona , J. L Cortes , R. Gracia-Ruiz , N. Loret

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

The precise progenitor system of type Ia supernovae (SNe Ia), whether it is a white dwarf (WD) close to the Chandrasekhar limit or substantially less massive, has been a matter of debate for decades. Recent research by our group on the…

Solar and Stellar Astrophysics · Physics 2022-09-28 Eduardo Bravo , Luciano Piersanti , Stéphane Blondin , Inma Domínguez , Oscar Straniero , Sergio Cristallo

In this paper, we review modified $f(R)$ theories of gravity in Palatini formalism. In this framework, , we use the Raychaudhuri's equation along with the requirement that the gravity is attractive, which holds for any geometrical theory of…

General Relativity and Quantum Cosmology · Physics 2021-03-02 H. Saiedi

Over the past several years, there has been enormous interest in massive neutron stars and white dwarfs due to either their direct or indirect evidence. The recent detection of gravitational wave event GW190814 has confirmed the existence…

High Energy Astrophysical Phenomena · Physics 2022-11-23 Banibrata Mukhopadhyay , Mukul Bhattacharya

The equations of state for degenerate electron and neutron gases are studied in the presence of magnetic fields. After including quantum effects to study the structural properties of these systems, it is found that some hypermagnetized…

White dwarfs are the remnants of stars not massive enough to become supernovae. This review explores the concept of strange dwarfs, a unique class of white dwarfs which contain cores of strange quark matter. Strange dwarfs have different…

Solar and Stellar Astrophysics · Physics 2024-12-06 Francesco Di Clemente , Alessandro Drago , Giuseppe Pagliara

We will briefly discuss the necessary conditions for stability of polytropies in $f(\hat R)$ Palatini gravity and the differences with the General Relativity ones.

General Relativity and Quantum Cosmology · Physics 2020-01-03 Aneta Wojnar

Recent discovery of several overluminous type Ia supernovae (SNe Ia) indicates that the explosive masses of white dwarfs may significantly exceed the canonical Chandrasekhar mass limit. Rapid differential rotation may support these massive…

High Energy Astrophysical Phenomena · Physics 2015-05-19 W. -M. Liu , W. -C. Chen , B. Wang , Z. W. Han

In this article we have extended the original work of Chandrasekhar on the structure of white dwarfs to the two-dimensional case. Although such two-dimensional stellar objects are hypothetical in nature, we strongly believe that the work…

Solar and Stellar Astrophysics · Physics 2015-02-20 Sanchari De , Somenath Chakrabarty

Pulsation modes have recently been observed in a handful of white dwarf (WD) primaries of cataclysmic variables, allowing an interesting new probe into the structure of accreting WD's. We briefly discuss the seismology of these objects, how…

Astrophysics · Physics 2007-05-23 Phil Arras , Dean Townsley , Lars Bildsten

We present calculations indicating the possibility of a new class of Type I supernovae. In this new paradigm relativistic terms enhance the self gravity of a carbon-oxygen white dwarf as it passes or orbits near a black hole. This…

Astrophysics · Physics 2009-11-10 J. R. Wilson , G. J. Mathews

Recent supernovae of type Ia measurements and other astronomical observations suggest that our universe is in accelerating phase of evolution at the present epoch. While a dark energy of unknown form is usually proposed as the most feasible…

Astrophysics · Physics 2008-11-26 Andrzej Borowiec , Wlodzimierz Godlowski , Marek Szydlowski

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

We study ultralight scalar fields with quadratic couplings to Standard-Model fermions and derive strong constraints from white-dwarf mass-radius data. Such couplings source scalar profiles inside compact stars, shift fermion masses, and can…

High Energy Physics - Phenomenology · Physics 2026-05-18 Kai Bartnick , Konstantin Springmann , Stefan Stelzl , Andreas Weiler

The evolution of the remnant of the merger of two white dwarfs is still an open problem. Furthermore, few studies have addressed the case in which the remnant is a magnetic white dwarf with a mass larger than the Chandrasekhar limiting…

Solar and Stellar Astrophysics · Physics 2018-05-02 L. Becerra , J. A. Rueda , P. Loren-Aguilar , E. Garcia-Berro

We analyze the effects of modified gravity on specific heats of electrons and ions, Debye temperature, crystallization process, and cooling mechanism in white dwarfs. We derive the Lane-Emden-Chandrasekhar equation and relate it to the…

General Relativity and Quantum Cosmology · Physics 2023-03-07 Surajit Kalita , Lupamudra Sarmah , Aneta Wojnar