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Related papers: Crystallized white dwarf stars in scalar-tensor gr…

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We study the effect of having a finite temperature on the equation of state and structure of a white dwarf. In order to keep the treatment as general as possible we carry on our discussion for ideal quantum gases obeying to both the…

Solar and Stellar Astrophysics · Physics 2017-11-20 Riccardo Fantoni

Recently, a new class of modified gravity theories formulated via an additional scalar and vector field on top of the standard tensor field has been proposed. The direct implications of these theories are expected to be relevant for…

General Relativity and Quantum Cosmology · Physics 2018-09-11 Phongpichit Channuie , Davood Momeni

Recently, some over-luminous Ia supernovaes are found, suggesting that their progenitors are white dwarfs more massive than the Chandrasekhar limit, which perhaps result from ultra-strong magnetic field inside the white dwarfs. We present…

High Energy Astrophysical Phenomena · Physics 2015-05-06 Qi-Xiang Zou , Xin-He Meng

In scalar-tensor theories of gravity, the equation of state of dark energy, w, can become smaller than -1 without violating any energy condition. The value of w today is tied to the level of deviations from general relativity which, in…

Astrophysics · Physics 2009-11-13 Jerome Martin , Carlo Schimd , Jean-Philippe Uzan

Theories of dark energy and modified gravity can be strongly constrained by astrophysical or cosmological observations, as illustrated by the recent observation of the gravitational wave event GW170817 and of its electromagnetic counterpart…

General Relativity and Quantum Cosmology · Physics 2018-11-02 David Langlois , Ryo Saito , Daisuke Yamauchi , Karim Noui

Scalar-tensor gravity models are among the prime candidates to explain cosmic acceleration, and compact stars provide unique laboratories for testing such theories. Predictions of scalar-tensor gravity in compact stars can be examined…

High Energy Astrophysical Phenomena · Physics 2025-10-08 Fahimeh Rahimi , Zeinab Rezaei , Adamu Issifu

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

In the presence of a strong magnetic field a stellar equilibrium configuration, aided by the Lorentz force, can support a larger mass than a non-magnetic one. This has been considered a possible explanation of the super-Chandrasekhar mass…

Solar and Stellar Astrophysics · Physics 2017-09-29 Prasanta Bera , Dipankar Bhattacharya

We investigate the hydrostatic equilibrium of white dwarfs within the framework of Rastall-Rainbow gravity, aiming to explore the effects of this modified gravitational theory on their properties. By employing the Chandrasekhar equation of…

General Relativity and Quantum Cosmology · Physics 2023-05-30 Jie Li , Bo Yang , Wenbin Lin

We recall the generalization of the Feynman-Metropolis-Teller approximation for a compressed atom using a relativistic Fermi-Thomas model. These results within a Wigner-Seitz approximation lead to a new equation of state for white dwarfs…

Astrophysics · Physics 2015-06-24 Remo J. Ruffini

We present follow-up spectroscopy and a detailed model atmosphere analysis of 29 wide double white dwarfs, including eight systems with a crystallized C/O core member. We use state-of-the-art evolutionary models to constrain the physical…

Solar and Stellar Astrophysics · Physics 2024-10-10 Manuel Barrientos , Mukremin Kilic , Pierre Bergeron , Simon Blouin , Warren R. Brown , Jeff J. Andrews

Many classes of extended scalar-tensor theories predict that dynamical instabilities can take place at high energies, leading to the formation of scalarized neutron stars. Depending on the theory parameters, stars in a scalarized state can…

General Relativity and Quantum Cosmology · Physics 2022-10-05 Hao-Jui Kuan , Arthur G. Suvorov , Daniela D. Doneva , Stoytcho S. Yazadjiev

Proto-neutron stars are born when a highly evolved and massive star collapses under gravity. In this paper, we investigate the spontaneous scalarization in proto-neutron stars. Based on the scalar tensor theory of gravity as well as the…

High Energy Astrophysical Phenomena · Physics 2025-10-08 Fahimeh Rahimi , Zeinab Rezaei

White dwarfs are a class of stars with unique physical properties. They present many challenging problems whose solution requires the application of advanced theories of dense matter, state-of-the-art experimental techniques, and extensive…

Solar and Stellar Astrophysics · Physics 2022-10-26 D. Saumon , S. Blouin , P. -E. Tremblay

Dark matter, an important portion of compact objects, can influence different phenomena in neutron stars. The spontaneous scalarization in the scalar-tensor gravity has been proposed for neutron stars. Here, we investigate the spontaneous…

High Energy Astrophysical Phenomena · Physics 2025-10-08 Fahimeh Rahimi , Zeinab Rezaei

A collection of modern, field-theoretical equations of state is applied to the investigation of cooling properties of compact stars. These comprise neutron stars as well as hypothetical strange matter stars, made up of absolutely stable…

Astrophysics · Physics 2009-10-28 Ch. Schaab , F. Weber , M. K. Weigel , N. K. Glendenning

Binary pulsar observations and gravitational wave detections seriously constrained scalar-tensor theories with massless scalar field allowing only small deviations from general relativity. If we consider a nonzero mass of the scalar field,…

General Relativity and Quantum Cosmology · Physics 2018-08-15 Kalin V. Staykov , Dimitar Popchev , Daniela D. Doneva , Stoytcho S. Yazadjiev

The equilibrium configuration of white dwarfs composed of a charged perfect fluid are investigated in the context of the $f(R,\mathcal{T})$ gravity, for which $R$ and $\mathcal{T}$ stand for the Ricci scalar and the trace of the…

General Physics · Physics 2020-05-13 F. Rocha , G. A. Carvalho , D. Deb , M. Malheiro

Quantum corrections can be important for diffusion and the melting temperature of dense plasmas in compact astrophysical objects, particulary white dwarfs and neutron stars. Typically ions in these systems are modeled classically, but…

Solar and Stellar Astrophysics · Physics 2015-03-19 Justin Mason

The vast majority of stars that populate the Universe will end their evolution as white-dwarf stars. Applications of white dwarfs include cosmochronology, evolution of planetary systems, and also as laboratories to study non-standard…

Solar and Stellar Astrophysics · Physics 2020-10-14 Alejandro H. Córsico