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We present a class of new relativistic solutions with anisotropic fluid for compact stars in hydrostatic equilibrium. The interior space-time geometry considered here for compact objects are described by parameters namely, $\lambda$, $k$,…

General Relativity and Quantum Cosmology · Physics 2016-03-25 Bikash Chandra Paul , Rumi Deb

A general formula of the symmetry energy for many-body interaction is proposed and the commonly used two-body interaction symmetry energy is recovered. Within Landau's theory (Lt), we generalize two equations of state (EoS) CCS$\delta$3 and…

Nuclear Theory · Physics 2015-07-03 H. Zheng , J. Sahagun , A. Bonasera

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

Neutron stars are commonly considered as astronomical objects having highdensity interiors and an inner core region in which various hadronic matter phases are expected. Several studies show that the inner structures affect macroscopic…

High Energy Astrophysical Phenomena · Physics 2016-06-22 Tomoki Endo

We construct analytic models of incompressible, rigidly rotating stars in PN gravity and study their stability against nonaxisymmetric Jacobi-like bar modes. PN configurations are modeled by homogeneous triaxial ellipsoids and the metric is…

General Relativity and Quantum Cosmology · Physics 2009-10-30 S. L. Shapiro , S. Zane

We have constructed star models consisting of four parts: (i) a homogeneous inner core with anisotropic pressure (ii) an infinitesimal thin shell separating the core and the envelope; (iii) an envelope of inhomogeneous density and isotropic…

General Relativity and Quantum Cosmology · Physics 2012-10-25 R. Chan , M. F. A. da Silva , J. F. Villas da Rocha

We construct constant rest-mass sequences of equilibrium models of differentially rotating neutron stars which resemble binary neutron star post-merger remnants. For a more realistic description of the post-merger remnant, we impose that…

High Energy Astrophysical Phenomena · Physics 2026-03-03 Georgios Lioutas , Panagiotis Iosif , Andreas Bauswein , Nikolaos Stergioulas

The past years have witnessed tremendous progress in understanding the properties of neutron stars and of the dense matter in their cores, made possible by electromagnetic observations of neutron stars and the detection of gravitational…

Among the possible extensions of General Relativity that have been put forward in order to address some long standing issues in our understanding of the Universe, Scalar-Tensor Theories have received a lot of attention for their simplicity.…

High Energy Astrophysical Phenomena · Physics 2020-08-12 J. Soldateschi , N. Bucciantini , L. Del Zanna

We study the existence and structure of static and slowly rotating neutron stars (NSs) in a particular truncation of scalar torsion theory with a scalar field $ \phi $ non-minimally coupled to the torsion scalar, and a potential of the form…

General Relativity and Quantum Cosmology · Physics 2024-12-31 Youcef Kehal , Khireddine Nouicer , Hamza Boumaza

In this work, we investigate the existence of neutron stars (NS) in the framework of $f$($\mathbb{T}$,$\mathcal{T}$) gravity, where $\mathbb{T}$ is the torsion tensor and $\mathcal{T}$ is the trace of the energy-momentum tensor. The…

High Energy Astrophysical Phenomena · Physics 2023-01-11 Clésio E. Mota , Luis C. N. Santos , Franciele M. da Silva , Cesar V. Flores , Iarley P. Lobo , Valdir B. Bezerra

We review various theoretical approaches for the equation of state (EoS) of dense matter, relevant for the description of core-collapse supernovae, compact stars and compact star mergers. The emphasis is put on models that are applicable to…

High Energy Astrophysical Phenomena · Physics 2017-04-05 M. Oertel , M. Hempel , T. Klähn , S. Typel

In this work, an exact solution of Einstein's field equations in isotropic coordinates for anisotropic matter distribution is obtained by considering a particular metric choice of metric potential $g_{rr}$. To check the feasibility of the…

General Relativity and Quantum Cosmology · Physics 2022-06-29 B. S. Ratanpal , Bhavesh Suthar

We study the evolution of magnetized and rigidly rotating neutron stars within a fully general relativistic implementation of ideal magnetohydrodynamics with no assumed symmetries in three spatial dimensions. The stars are modeled as…

General Relativity and Quantum Cosmology · Physics 2010-08-24 Steven L. Liebling , Luis Lehner , David Neilsen , Carlos Palenzuela

The structure of neutron stars is considered from theoretical and observational perspectives. We demonstrate an important aspect of neutron star structure: the neutron star radius is primarily determined by the behavior of the pressure of…

Astrophysics · Physics 2008-11-26 J. M. Lattimer , M. Prakash

A simple classification is given of the anisotropic relativistic star models, resembling the one of charged isotropic solutions. On the ground of this database, and taking into account the conditions for physically realistic star models, a…

General Relativity and Quantum Cosmology · Physics 2018-01-24 B. V. Ivanov

Numerous models of neutron star (NS) equation of state (EoS) exist based on different superdense-matter physics approaches. Nevertheless, some NS properties show universal (EoS-independent) relations. Here, we propose a novel class of such…

High Energy Astrophysical Phenomena · Physics 2024-08-02 Dmitry D. Ofengeim , Peter S. Shternin , Tsvi Piran

We derive the equation for pressure within a neutron star, taking into account a non-zero cosmological constant ($\Lambda$). We then examine the stability of the neutron star's equilibrium state in the presence of cosmological constant. Our…

General Relativity and Quantum Cosmology · Physics 2025-04-22 Naveen K. Singh , Gopal Kashyap

Quasi-local variables, i.e. quantities whose values can be derived from physics accessible within an arbitrarily small neighborhood of a spacetime point, are used to construct the equation of state (EoS) for the anisotropic fluid in the…

General Relativity and Quantum Cosmology · Physics 2011-01-20 Dubravko Horvat , Sasa Ilijic , Anja Marunovic

Planets that orbit only one of the stars in stellar binary systems (i.e., circumstellar) are dynamically constrained to a limited range of orbital parameters and thus understanding conditions on their stability is of great importance in…

Earth and Planetary Astrophysics · Physics 2020-02-11 Billy Quarles , Gongjie Li , Veselin Kostov , Nader Haghighipour