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Related papers: On "hard stars" in general relativity

200 papers

We construct a family of steady solutions to the two-dimensional incompressible Euler equation in a general bounded domain, such that the vorticity is supported in two well-separated regions of small diameter and converges to a pair of…

Analysis of PDEs · Mathematics 2023-01-19 Guodong Wang , Bijun Zuo

We establish the existence of a stable family of solutions to the Euler equations on Kasner backgrounds near the singularity with the full expected asymptotic data degrees of freedom and no symmetry or isotropy restrictions. Existence is…

Analysis of PDEs · Mathematics 2025-02-17 Florian Beyer , Todd A. Oliynyk

We find two new classes of exact solutions to the Einstein-Maxwell system of equations. The matter distribution satisfies a linear equation of state consistent with quark matter. The field equations are integrated by specifying forms for…

General Relativity and Quantum Cosmology · Physics 2015-06-23 Jefta M. Sunzu , Sunil D. Maharaj , Subharthi Ray

We establish the existence of $1$-parameter families of $\epsilon$-dependent solutions to the Einstein-Euler equations with a positive cosmological constant $\Lambda >0$ and a linear equation of state $p=\epsilon^2 K \rho$, $0<K\leq 1/3$,…

General Relativity and Quantum Cosmology · Physics 2018-06-21 Chao Liu , Todd A. Oliynyk

The properties of neutron stars are investigated within the relativistic central variational method by using a realistic nucleon-nucleon ($NN$) interaction. The strong repulsion of realistic $NN$ interactions at short distances is treated…

Nuclear Theory · Physics 2017-03-08 Jinniu Hu , Hong Shen , Hiroshi Toki

We prove general nonlinear stability and existence theorems for rotating star solutions which are axi-symmetric steady-state solutions of the compressible isentropic Euler-Poisson equations in 3 spatial dimensions. We apply our results to…

General Relativity and Quantum Cosmology · Physics 2014-08-04 Tao Luo , Joel Smoller

In the present paper we investigate the structure of relativistic stars in 4D Einstein-Gauss-Bonnet gravity. The mass-radius relations are obtained for realistic hadronic and for strange quark star equations of state, and for a wide range…

General Relativity and Quantum Cosmology · Physics 2021-05-19 Daniela D. Doneva , Stoytcho S. Yazadjiev

We prove uniform finite-time existence of solutions to the vacuum Einstein equations in polarized U(1) symmetry which have uniformly positive incoming $H^1$ energy supported on an arbitrarily small set in the 2 + 1 spacetime obtained by…

General Relativity and Quantum Cosmology · Physics 2024-06-14 Spyros Alexakis , Nathan Thomas Carruth

We describe two fitting schemes that aim to represent the high-density part of realistic equations of state for numerical simulations such as neutron star oscillations. The low-density part of the equation of state is represented by an…

High Energy Astrophysical Phenomena · Physics 2024-05-20 Gaël Servignat , Philip J. Davis , Jérôme Novak , Micaela Oertel , José A. Pons

We perform fully relativistic calculations of binary neutron stars in quasi-equilibrium circular orbits. We integrate Einstein's equations together with the relativistic equation of hydrostatic equilibrium to solve the initial value problem…

General Relativity and Quantum Cosmology · Physics 2009-10-30 T. W. Baumgarte , G. B. Cook , M. A. Scheel , S. L. Shapiro , S. A. Teukolsky

We study the stability of three analytical solutions of the Einstein's field equations for spheres of fluid. These solutions are suitable to describe compact objects including white dwarfs, neutron stars and supermassive stars and they have…

General Relativity and Quantum Cosmology · Physics 2017-05-04 Ch. C. Moustakidis

The classical model of a star is the Lane-Emden star with dynamics governed by the Euler-Poisson equations. We consider the case of a liquid star with a "stiffened gas" equation of state $p=\rho^\gamma-1$. We derive the full 3D linearised…

Analysis of PDEs · Mathematics 2026-03-05 King Ming Lam

We investigate the nuclear symmetry energy and neutron star properties using a Bayesian analysis based on constraints from different chiral effective field theory calculations using new energy density functionals that allow for large…

Nuclear Theory · Physics 2024-03-12 Yeunhwan Lim , Achim Schwenk

The macroscopic properties of compact stars in modified gravity theories can be significantly different from the general relativistic (GR) predictions. Within the gravitational context of scalar-tensor theories, with a scalar field $\phi$…

General Relativity and Quantum Cosmology · Physics 2023-12-05 Juan M. Z. Pretel , Sergio E. Jorás , Ribamar R. R. Reis , Sergio B. Duarte , José D. V. Arbañil

The observable macroscopic properties of relativistic stars (whose equations of state are known) can be predicted by solving the stellar structure equations that follow from Einstein's equation. For neutron stars, however, our knowledge of…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Lee Lindblom

We study the properties of neutron stars adopting relativistic equations of state of neutron star matter, calculated in the framework of the relativistic Brueckner-Hartree-Fock approximation for electrically charge neutral neutron star…

Nuclear Theory · Physics 2009-10-30 H. Huber , F. Weber , M. K. Weigel , Ch. Schaab

We study the Einstein static universe in the framework of Generalized Uncertainty Principle constructed by the Snyder non-commutative space. It is shown that the deformation parameter can induce an effective energy density subject to GUP…

General Relativity and Quantum Cosmology · Physics 2019-05-01 F. Darabi , K. Atazadeh

We construct the first dynamically stable ergostars (equilibrium neutron stars that contain an ergoregion) for a compressible, causal equation of state. We demonstrate their stability by evolving both strict and perturbed equilibrium…

General Relativity and Quantum Cosmology · Physics 2019-12-11 Antonios Tsokaros , Milton Ruiz , Lunan Sun , Stuart L. Shapiro , Kōji Uryū

Quasi-equilibrium sequences of binary neutron stars are constructed for a variety of equations of state in general relativity. Einstein's constraint equations in the Isenberg-Wilson-Mathews approximation are solved together with the…

Solar and Stellar Astrophysics · Physics 2015-05-18 Keisuke Taniguchi , Masaru Shibata

The hydrodynamic evolution of self-gravitating gaseous stars is governed by the Euler-Poisson equations. We study the structure of the linear approximation of barotropic perturbations around spherically symmetric equilibria based on…

Analysis of PDEs · Mathematics 2020-05-15 Juhi Jang , Tetu Makino