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Related papers: Compact stars in Rastall gravity: hydrostatic equi…

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Radial mode stability is a necessary condition for the astrophysical viability of compact objects. In recent years, astrophysical models with two fluids have gain popularity, especially in their ability to model dark matter admixed neutron…

General Relativity and Quantum Cosmology · Physics 2024-12-09 Daniel A. Caballero , Justin L. Ripley , Nicolás Yunes

The Rastall gravity is a modification of Einstein's general relativity, in which the energy-momentum conservation is not satisfied and depends on the gradient of the Ricci curvature. It is in dispute whether the Rastall gravity is…

Astrophysics of Galaxies · Physics 2020-08-26 Meirong Tang , Zhaoyi Xu , Jiancheng Wang

In the context of the standard model of particle physics, there is a definite upper limit to the density of stable compact stars. However, if there is a deeper layer of constituents, below that of quarks and leptons, stability may be…

Astrophysics · Physics 2014-10-13 F. Sandin

In this study we consider the nonlinear radial oscillations exciting in LBV--stars with effective temperatures 1.5e4 K <= Teff <= 3e4 K, bolometric luminosities 1.2e6 L_odot <= L <= 1.9e6 L_odot and masses 35.7 M_odot <= M <= 49.1 M_odot.…

Solar and Stellar Astrophysics · Physics 2015-05-13 Yu. A. Fadeyev

We investigate the rotational core collapse of a rapidly rotating relativistic star by means of a 3+1 hydrodynamical simulations in conformally flat spacetime of general relativity. We concentrate our investigation to the bounce of the…

Astrophysics · Physics 2007-05-23 Motoyuki Saijo

The aim of this paper is to perform stability analysis of anisotropic dissipative cylindrical collapsing model in $f(R,T,R_{\mu\nu} T^{\mu\nu})$ gravity. In this context, the modified version of hydrodynamical equation is explored by means…

General Relativity and Quantum Cosmology · Physics 2017-09-14 Z. Yousaf , M. Zaeem-ul-Haq Bhatti , Ume Farwa

We study static, spherically symmetric, self-gravitating systems minimally coupled to a scalar field with U(1) gauge symmetry: charged boson stars. We find numerical solutions to the EinsteinMaxwell equations coupled to the relativistic…

High Energy Astrophysical Phenomena · Physics 2013-08-05 Daniela Pugliese , Hernando Quevedo , Jorge A. Rueda H. , Remo Ruffini

Radial pulsations of newborn neutron stars (protoneutron stars) are studied for a range of internal temperatures and entropies per baryon predicted by the existing numerical simulations. Protoneutron star models are constructed using a…

Astrophysics · Physics 2008-11-26 D. Gondek , P. Haensel , J. L. Zdunik

We present a generalization of Rastall's gravity in which the conservation law of the energy-momentum tensor is altered, and as a result, the trace of the energy-momentum tensor is taken into account together with the Ricci scalar in the…

General Relativity and Quantum Cosmology · Physics 2022-02-24 Clésio E. Mota , Luis C. N. Santos , Franciele M. da Silva , Guilherme Grams , Iarley P. Lobo , Débora P. Menezes

We perform a detailed analysis of radial oscillations to discuss dynamical stability in two-fluid neutron stars composed of ordinary nuclear matter and a gravitationally coupled dark matter component. Using a fully relativistic two-fluid…

High Energy Astrophysical Phenomena · Physics 2025-09-05 Ankit Kumar , Hajime Sotani

We obtain equilibrium solutions for rotating compact stars including the special relativistic effects. The gravity is assumed to be Newtonian, but we used the active mass density, which takes into account all the energies such as motions of…

High Energy Astrophysical Phenomena · Physics 2015-05-13 Jinho Kim , Hee Il Kim , Hyung Mok Lee

We study the dynamical instability against bar-mode deformation of differentially rotating stars. We performed numerical simulation and linear perturbation analysis adopting polytropic equations of state with the polytropic index $n=1$. It…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Masaru Shibata , Shigeyuki Karino , Yoshiharu Eriguchi

When a relativistic star rotates slowly and rigidly, centrifugal forces flatten it slightly, thereby catalyzing a small admixture of quadrupolar vibration into its radial modes and a damping of the resulting quasi-radial modes. The damping…

General Relativity and Quantum Cosmology · Physics 2025-09-09 James B. Hartle , Kip S. Thorne

We study non-rotating and isotropic strange quark stars in Lorentz-violating theories of gravity, and in particular in Ho\v{r}ava gravity and Einstein-{\ae}ther theory. For quark matter we adopt both linear and non-linear equations of…

General Relativity and Quantum Cosmology · Physics 2020-06-22 Grigoris Panotopoulos , Daniele Vernieri , Ilídio Lopes

Within the context of energy-momentum squared gravity (EMSG), where non-linear matter contributions appear in the gravitational action, we derive the modified TOV equations describing the hydrostatic equilibrium of charged compact stars. We…

General Relativity and Quantum Cosmology · Physics 2023-08-21 Juan M. Z. Pretel , Takol Tangphati , Ayan Banerjee

In this paper we used the theory of adiabatic radial oscillations developed by Chandrasekhar to study the conditions for dynamical stability of constant energy-density stars, or Schwarzschild stars, in the unstudied ultra compact regime…

General Relativity and Quantum Cosmology · Physics 2019-02-20 Camilo Posada , Cecilia Chirenti

Stochastic perturbations (radial) of a spherically symmetric relativistic star, modeled by a perfect fluid in comoving coordinates for the collapse scenario are worked out using the classical Einstein- Langevin equation, which has been…

General Relativity and Quantum Cosmology · Physics 2019-04-09 Seema Satin

We present numerical results on the hydrodynamic stability of coalescing binary stars in the first post Newtonian(1PN) approximation of general relativity. We pay particular attention to the hydrodynamical instability of corotating binary…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Masaru Shibata , Ken-ichi Oohara , Takashi Nakamura

This paper delves into the impact of extended symmetric teleparallel theory on anisotropic compact stellar structures. The explicit field equations were formulated by considering a minimum model of this extended gravity. Basically, the…

General Relativity and Quantum Cosmology · Physics 2025-05-01 M. Zeeshan Gul , M. Sharif , Adeeba Arooj , Baiju Dayanandan

We complete the stability study of general relativistic spherically symmetric polytropic perfect fluid spheres, concentrating attention to the newly discovered polytropes containing region of trapped null geodesics. We compare the methods…

General Relativity and Quantum Cosmology · Physics 2020-05-14 Jan Hladík , Camilo Posada , Zdeněk Stuchlík
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