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Related papers: Neutron stars in Starobinsky model

200 papers

We contribute a publicly available set of tables and code to provide Equations of State (EoS) for matter at neutron star densities. Our EoSes are constrained only by input from hadron physics and fundamental principles, without feedback…

General Relativity and Quantum Cosmology · Physics 2021-03-24 Eva Lope Oter , Andreas Windisch , Felipe J. Llanes-Estrada , Mark Alford

In the present paper we generate a set of solutions describing the interior of a compact star under $f(R,T)$ theory of gravity which admits conformal motion. We consider the equation of state (EOS) $p=\omega\rho$ with $0<\omega<1$ for the…

General Relativity and Quantum Cosmology · Physics 2016-12-20 Amit Das , Farook Rahaman , B. K. Guha , Saibal Ray

We provide the modified TOV equations for the hydrostatic equilibrium of charged compact stars within the metric $f(R)$ gravitational background. We adopt the MIT bag model EoS for the dense matter and assume a charge distribution where the…

General Relativity and Quantum Cosmology · Physics 2022-09-23 Juan M. Z. Pretel , José D. V. Arbañil , Sergio B. Duarte , Sergio E. Jorás , Ribamar R. R. Reis

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

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

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

High Energy Astrophysical Phenomena · Physics 2010-01-11 Pierre M. Pizzochero

We perform a model-agnostic Bayesian analysis of the neutron-star-matter equation of state (EoS), using known ab-initio constraints and astrophysical observations to limit its behavior at intermediate densities. Permitting explicit…

High Energy Astrophysical Phenomena · Physics 2025-12-23 Sofia Blomqvist , Christian Ecker , Tyler Gorda , Aleksi Vuorinen

In the present paper we investigate self-consistently slowly rotating neutron and strange stars in R-squared gravity. For this purpose we first derive the equations describing the structure of the slowly rotating compact stars in…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Kalin V. Staykov , Daniela D. Doneva , Stoytcho S. Yazadjiev , Kostas D. Kokkotas

The equation-of-state (EOS) parameter $\phi \equiv P/\varepsilon$, defined as the ratio of pressure to energy density, encapsulates the fundamental response of matter under extreme compression. Its value at the center of the most massive…

Nuclear Theory · Physics 2026-01-07 Bao-Jun Cai , Bao-An Li , Yu-Gang Ma

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

We study the structure of neutron stars in R+\beta\ R^{\mu \nu} R_{\mu \nu} gravity model with perturbative method. We obtain mass--radius relations for six representative equations of state (EoSs). We find that, for |\beta| ~ 10^11 cm^2,…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Cemsinan Deliduman , K. Y. Ekşi , Vildan Keleş

We study stellar configurations and the space-time around them in metric $f(R)$ theories of gravity. In particular, we focus on the polytropic model of the Sun in the $f(R)=R-\mu^4/R$ model. We show how the stellar configuration in the…

Astrophysics · Physics 2008-12-18 K. Henttunen , T. Multamaki , I. Vilja

The thermodynamical properties of the equation of state (EoS) of high-density matter (above nuclear saturation density) and the possible existence of exotic states such as phase transitions from nuclear/hadronic matter into quark-gluon…

High Energy Astrophysical Phenomena · Physics 2019-01-28 M. A. Aloy , J. M. Ibáñez , N. Sanchis-Gual , M. Obergaulinger , J. A. Font , S. Serna , A. Marquina

The study of neutron stars, or more general compact stars, is a topic of central interest in nuclear astrophysics. Furthermore, neutron stars serve as the only physical systems whose properties can be used to infer information on cold and…

Solar and Stellar Astrophysics · Physics 2013-07-19 S. Schramm , V. Dexheimer , R. Negreiros , T. Schürhoff , J. Steinheimer

In the present paper we investigate non-perturbatively and self-consistently the structure of neutron stars in $R$-squared gravity by simultaneously solving the interior and exterior problem. The mass-radius relations are obtained for…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Stoytcho S. Yazadjiev , Daniela D. Doneva , Kostas D. Kokkotas , Kalin V. Staykov

Models of neutron stars (NSs) with hyperon cores are constructed with an effective chiral model in mean-field approximation. The hyperon couplings are fixed by reproducing their experimentally determined binding energies. The impact of…

Nuclear Theory · Physics 2019-01-31 Debashree Sen , Kinjal Banerjee , T. K. Jha

Quartic gravity theory is considered with the Einstein-Hilbert Lagrangean $R+aR^{2}+bR_{\mu \nu}R^{\mu \nu},$ $R_{\mu \nu}$ being Ricci\'s tensor and R the curvature scalar. The parameters $a$ and $b$ are taken of order 1 km$^{2}.$…

General Relativity and Quantum Cosmology · Physics 2021-06-16 Emilio Santos

With an average density higher than the nuclear density, neutron stars (NS) provide a unique test-ground for nuclear physics, quantum chromodynamics (QCD), and nuclear superfluidity. Determination of the fundamental interactions that govern…

In this work, we explore the eternal collapsing phenomenon of a stellar system (e.g., a star) within the framework of $f(R)$ gravity and investigate some new aspects of the continued homogeneous gravitational collapse with perfect fluid…

General Relativity and Quantum Cosmology · Physics 2023-11-30 Annu Jaiswal , Rajesh Kumar , Sudhir Kumar Srivastava , Megandhren Govender

Neutron stars and their mergers provide the highest-density regime in which Einstein's equations in full (with a matter source) can be tested against modified theories of gravity. But doing so requires a priori knowledge of the Equation of…

High Energy Physics - Phenomenology · Physics 2022-02-09 Eva Lope-Oter , Felipe J. Llanes-Estrada