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Related papers: Realistic neutron star models in $f(T)$ gravity

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Neutron stars are among the densest known objects in the universe and an ideal laboratory for the strange physics of super-condensed matter. While the simultaneously measurements of mass and radius of non-rotating neutron stars may impose…

Nuclear Theory · Physics 2020-02-03 P. S. Koliogiannis , Ch. C. Moustakidis

We numerically construct compact stars in the scalar-tensor theory of gravity with non-minimal derivative coupling of a scalar field to the curvature and nonzero cosmological constant. There are two free parameters in this model of gravity:…

General Relativity and Quantum Cosmology · Physics 2025-04-08 P. E. Kashargin , A. A. Lebedev , S. V. Sushkov

We study the structure of neutron stars in $f(R)=R+\alpha R^{2}$ theory of gravity (Starobinsky model), in an exact and non-perturbative approach. In this model, apart from the standard General Relativistic junction conditions, two extra…

General Relativity and Quantum Cosmology · Physics 2014-05-01 Apratim Ganguly , Radouane Gannouji , Rituparno Goswami , Subharthi Ray

The realistic models of neutron stars are considered for simple $R+\alpha R^2$ gravity and equivalent Brance-Dicke theory with dilaton field in Einsein frame. For negative values of $\alpha$ we have no acceptable results from astrophysical…

General Relativity and Quantum Cosmology · Physics 2018-12-27 Artyom V. Astashenok , Alexey S. Baigashov , Sergey A. Lapin

Astrophysical observations of neutron stars probe the structure of dense nuclear matter and have the potential to reveal phase transitions at high densities. Most recent analyses are based on parametrized models of the equation of state…

High Energy Astrophysical Phenomena · Physics 2025-05-13 Reed Essick , Isaac Legred , Katerina Chatziioannou , Sophia Han , Philippe Landry

We investigate the oscillations of neutron stars using a purely Newtonian approach and three other pseudo-Newtonian formulations. Our work is motivated by the fact that pseudo-Newtonian formulations are commonly used in core-collapse…

High Energy Astrophysical Phenomena · Physics 2023-09-08 Yat-To Tang , Lap-Ming Lin

We present a brief review of general results about non-rotating neutron stars in simple R-square gravity and its extension with a scalar axion field. Modified Einstein equations are presented for metrics in isotropical coordinates. The…

General Relativity and Quantum Cosmology · Physics 2020-07-08 Artyom V. Astashenok , Sergei D. Odintsov

We study rapidly spinning compact stars with equations of state featuring a first order phase transition between strongly coupled nuclear matter and deconfined quark matter by employing the gauge/gravity duality. We consider a family of…

High Energy Astrophysical Phenomena · Physics 2021-02-10 Tuna Demircik , Christian Ecker , Matti Järvinen

We study neutron star configurations in a simple shift-symmetric subfamily of degenerate higher-order scalar-tensor (DHOST) theories, whose deviations from General Relativity (GR) are characterized by a single parameter. We compute the…

General Relativity and Quantum Cosmology · Physics 2022-11-09 Hamza Boumaza , David Langlois

We study the Starobinsky or $R^2$ model of $f(R)=R+\alpha R^2$ for neutron stars with the structure equations represented by the coupled differential equations and the \emph{polytropic} type of the matter equation of state. The junction…

General Relativity and Quantum Cosmology · Physics 2017-10-11 Wei-Xiang Feng , Chao-Qiang Geng , W. F. Kao , Ling-Wei Luo

We find some exact solutions for constant-density and quark matter equations of state in stellar structure models framed within the $f(R,T)=R+\lambda \kappa^2 T$ theory of gravity, where $R$ is the curvature scalar, $T$ the trace of the…

General Relativity and Quantum Cosmology · Physics 2025-04-09 Aliya Batool , Abdul Malik Sultan , Gonzalo J. Olmo , Diego Rubiera-Garcia

We investigate the slowly rotating general relativistic superfluid neutron stars including the entrainment effect in a two-fluid model, where one fluid represents the superfluid neutrons and the other is the charge-neutral fluid called the…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Apurba Kheto , Debades Bandyopadhyay

Superfluid neutron matter is a key ingredient in the composition of neutron stars. The physics of the inner crust is largely dependent on that of its $S$-wave neutron superfluid which has made its presence known through pulsar glitches and…

Nuclear Theory · Physics 2021-02-03 Georgios Palkanoglou , Alexandros Gezerlis

We investigate the causal limit of maximum mass for stars in the framework of$f(R)$ gravity. We choose a causal equation of state, with variable speed of sound, and with the transition density and pressure corresponding to the SLy equation…

General Relativity and Quantum Cosmology · Physics 2021-04-07 A. V. Astashenok , S. Capozziello , S. D. Odintsov , V. K. Oikonomou

We investigate how a phase transition from neutron-star matter to spin-polarized neutron matter affects the equation of state and mass-radius relation of neutron stars. While general extension schemes for the equation of state allow for…

Nuclear Theory · Physics 2020-03-25 I. Tews , A. Schwenk

We investigate equilibrium configurations of uniformly rotating neutron stars in $R^2$ gravity with axion scalar field for GM1 equation of state (EoS) for nuclear matter. The mass-radius diagram, mass-central energy density are presented…

General Relativity and Quantum Cosmology · Physics 2020-09-09 Artyom V. Astashenok , Sergey D. Odintsov

We present the interior solutions of distributions of magnetised fluid inside a sphere in $f(R,T)$ gravity. The magnetised sphere is embedded in an exterior Reissner-Nordstr\"{o}m metric. We assume that all physical quantities are in static…

General Physics · Physics 2018-12-07 Safiqul Islam , Shantanu Basu

We develop the general theory of stars in Saa's model of gravity with propagating torsion and study the basic stationary state of neutron star. Our numerical results show that the torsion force decreases the role of the gravity in the star…

General Relativity and Quantum Cosmology · Physics 2010-11-19 T. Boyadjiev , P. Fiziev , S. Yazadjiev

The so-called hyperon puzzle in the theory of neutron stars is considered in the framework of modified $f(R)$ gravity. We show that for simple hyperon equations of state, it is possible to obtain the maximal neutron star mass which…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Artyom V. Astashenok , Salvatore Capozziello , Sergei D. Odintsov

Recent advances in nuclear theory combined with new astrophysical observations have led to the need for specific theoretical models that actually apply to phenomena on dense-matter physics. At the same time, quantum chromodynamics (QCD)…

General Relativity and Quantum Cosmology · Physics 2022-08-30 Juan M. Z. Pretel , Takol Tangphati , Ayan Banerjee , Anirudh Pradhan
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