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Neutron stars are the densest objects in the Universe. In this paper we consider so-called inner crust - the layer, where neutron-excess nuclei are immersed into degenerate gas of electrons and sea of quasi-free neutrons. It was generally…

Nuclear Theory · Physics 2022-09-14 Nikita A. Zemlyakov , Andrey I. Chugunov

Many of exoplanetary systems consist of more than one planet and the study of planetary orbits with respect to their long-term stability is very interesting. Furthermore, many exoplanets seem to be locked in a mean-motion resonance (MMR),…

Earth and Planetary Astrophysics · Physics 2017-02-10 Kyriaki I. Antoniadou

Properties, structure, and thermal evolution of neutron stars are determined by the equation of state of stellar matter. Recent data on isospin-diffusion and isoscaling in heavy-ion collisions at intermediate energies as well as the size of…

Astrophysics · Physics 2009-11-13 Plamen G. Krastev , Bao-An Li , Aaron Worley

Based on the relativistic mean field (RMF) model with Thomas-Fermi approximation, we investigate the elastic properties of neutron star matter. The elastic constants are estimated by introducing deformations on the nuclear pasta structures…

This work is based on stability analysis of spherically symmetric collapsing star surrounding in locally anisotropic environment in $f(R,T)$ gravity, where $R$ is Ricci scalar and $T$ corresponds to the trace of energy momentum tensor.…

General Physics · Physics 2014-11-26 Ifra Noureen , M. Zubair

We describe a novel class of geometrical models of relativistic stars. Our approach to the static spherically symmetric solutions of Einstein equations is based on a careful physical analysis of radial gauge conditions. It brings us to a…

Astrophysics · Physics 2007-05-23 P. P. Fiziev

In the present paper we have constructed a new relativistic anisotropic compact star model having a spherically symmetric metric of embedding class one. Here we have assumed an arbitrary form of metric function and solved the Einstein…

General Relativity and Quantum Cosmology · Physics 2017-07-26 Piyali Bhar , Ksh. Newton Singh , Tuhina Manna

We present equilibrium sequences of rotating relativistic stars, constructed with a new rotation law that was proposed by Uryu et al. (2017). We choose rotational parameters motivated by simulations of binary neutron star merger remnants,…

General Relativity and Quantum Cosmology · Physics 2021-03-25 Panagiotis Iosif , Nikolaos Stergioulas

In this lecture, we give a first introduction to neutron stars, based on fundamental physical principles. After outlining their outstanding macroscopic properties, as obtained from observations, we infer the extreme conditions of matter in…

High Energy Astrophysical Phenomena · Physics 2016-09-27 Pierre M. Pizzochero

The main purpose of this paper is to obtain physically stable stellar models coupled with anisotropic matter distribution in the context of $f(\mathcal{R},\mathrm{T}^{2})$ theory. For this, we consider a static spherical geometry and…

General Relativity and Quantum Cosmology · Physics 2024-06-06 Tayyab Naseer , M. Sharif , Sana Manzoor , Arooj Fatima

This article presents a new model for anisotropic compact stars that are confined to physical dark matter in the background of $f(T)$ teleparallel gravity. The model is based on the equation of state (EoS) of the bag model type and the…

General Relativity and Quantum Cosmology · Physics 2024-08-06 Samprity Das , Prabir Rudra , Surajit Chattopadhyay

In the context of the space-based mission CoRoT, devoted to asteroseismology and search for planet transits, we analyse the accuracy of fundamental stellar parameters (mass, radius, luminosity) that can be obtained from asteroseismological…

Solar and Stellar Astrophysics · Physics 2015-05-13 C. Mulet-Marquis , I. Baraffe , S. Aigrain , F. Pont

We determine an empirical dense matter equation of state from a heterogeneous dataset of six neutron stars: three type I X-ray bursters with photospheric radius expansion, studied by Ozel et al., and three transient low-mass X-ray binaries.…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Andrew W. Steiner , James M. Lattimer , Edward F. Brown

We use a modified Einstein-Maxwell gravity to study stability of an electrostatic spherical star. Correction terms in this model are scalers which are made from contraction of Ricci tensor and electromagnetic vector potential. Our…

General Relativity and Quantum Cosmology · Physics 2023-12-05 Hossein Ghaffarnejad , Tohid Ghorbani , Firoozeh Eidizadeh

In this work, we investigate static configurations of dark energy stars within the framework of Rastall-Rainbow (R-R) gravity, which combines an energy-dependent deformation of spacetime with a nonminimal coupling between matter and…

General Relativity and Quantum Cosmology · Physics 2025-10-21 Ayan Banerjee , Bobur Turimov , Sulton Usanov , Murodbek Vapaev , Yunus Turaev , Zebo Avezmuratova

The macroscopic model for a neutron star (NS) as a perfect liquid drop at equilibrium is extended to rotating systems with a small frequency $\omega $ within the effective-surface (ES) approach. The gradient surface terms of the NS energy…

High Energy Astrophysical Phenomena · Physics 2025-08-18 A. A. Uleiev , A. G. Magner , S. P. Maydanyuk , A. Bonasera , H. Zheng , S. N. Fedotkin , A. I. Levon , U. V. Grygoriev , T. Depastas

In static and spherically symmetric spacetime, we solve the Einstein Maxwell equations. The effective gravitational potential and the electric field for charged anisotropic fluid are defined in terms of two free parameters. For such…

Solar and Stellar Astrophysics · Physics 2017-02-20 Safiqul Islam , Satadal Datta , Tapas K Das

The orbital solutions of published multi-planet systems are not necessarily dynamically stable on timescales comparable to the lifetime of the system as a whole. For this reason, dynamical tests of the architectures of proposed exoplanetary…

Earth and Planetary Astrophysics · Physics 2020-11-30 J. P. Marshall , J. Horner , R. A. Wittenmyer , J. T. Clark , M. W. Mengel

We construct equilibrium configurations of uniformly rotating neutron stars for selected relativistic mean-field nuclear matter equations of state (EOS). We compute in particular the gravitational mass ($M$), equatorial ($R_{\rm eq}$) and…

Solar and Stellar Astrophysics · Physics 2015-08-06 Federico Cipolletta , Christian Cherubini , Simonetta Filippi , Jorge A. Rueda , Remo Ruffini

Bose-Einstein condensates (BECs) have been proposed as candidate states of matter for the interior of neutron stars. Specifically, Chavanis and Harko obtained the mass-radius relation for a BEC star and proposed that the recently discovered…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Arunava Mukherjee , Shreya Shah , Sukanta Bose