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Related papers: Massive Neutron Star Models with Parabolic Cores

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Recent measurement of mass of PSR J1614-2230 rules out most of existing models of equation of state (EOS) of dense matter with high-density softening due to hyperonization, based on the recent hyperon-nucleon and hyperon-hyperon…

Solar and Stellar Astrophysics · Physics 2014-01-31 J. L. Zdunik , P. Haensel

We discuss neutron stars with strong magnetic mean fields in the framework of Extended Theories of Gravity. In particular, we take into account models derived from $f(R)$ and $f(\cal G)$ extensions of General Relativity where functions of…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Artyom V. Astashenok , Salvatore Capozziello , Sergei D. Odintsov

We investigated realistic neutron stars in axion $R^{2}$ gravity. The coupling between curvature and axion field $\phi$ is assumed in the simple form $\sim R^2\phi$. For the axion mass in the range $m_{a}\sim 10^{-11}-10^{-10}$ eV the…

General Relativity and Quantum Cosmology · Physics 2020-01-29 Artyom V. Astashenok , Sergey D. Odintsov

The measurement or constraint of the masses of neutron stars and their binary companions tests theories of neutron star structure and of pulsar formation and evolution. We have measured the rate of the general relativistic advance of the…

Astrophysics · Physics 2009-10-22 S. E. Thorsett , Z. Arzoumanian , M. M. McKinnon , J. H. Taylor

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

We examine the roles the presence of hyperons in the cores of neutron stars may play in determining global properties of these stars. The study is based on estimates that hyperons appear in neutron star matter at about twice the nuclear…

Astrophysics · Physics 2009-10-31 Shmuel Balberg , Itamar Lichtenstadt , Gregory. B. Cook

We show that the widely used parabolic approximation to the Equation of State (EOS) of asymmetric nuclear matter leads systematically to significantly higher core-crust transition densities and pressures. Using an EOS for neutron-rich…

Nuclear Theory · Physics 2010-03-04 Lie-Wen Chen , Bao-An Li , Hong-Ru Ma , Jun Xu

Recent NICER observation data on PSR J0030+0451 has recently added a unique mass-radius constraint on the properties of the superdense nuclear matter existing in the interior of compact stars. Such a macroscopic data restrict further the…

High Energy Astrophysical Phenomena · Physics 2022-02-14 Péter Pósfay , Gergely Gábor Barnaföldi , Antal Jakovác

Three-dimensional hydrodynamical, Newtonian calculations of the coalescence of equal-mass binary neutron stars are performed, including a physical high-density equation of state and a treatment of the neutrino emission of the heated matter.…

Astrophysics · Physics 2009-09-25 M. Ruffert , H. -Th. Janka , K. Takahashi , G. Schaefer

The oscillation of neutrons $n$ into mirror neutrons $n'$, their mass degenerate partners from dark mirror sector, can have interesting implications for neutron stars: an ordinary neutron star could gradually transform into a mixed star…

High Energy Astrophysical Phenomena · Physics 2021-12-08 Zurab Berezhiani , Riccardo Biondi , Massimo Mannarelli , Francesco Tonelli

The equation of state of beta-stable and charge neutral nucleonic matter is computed within the SU(2) parity doublet model in mean field and in the relativistic Hartree approximation. The mass of the chiral partner of the nucleon is assumed…

Nuclear Theory · Physics 2008-11-26 V. Dexheimer , G. Pagliara , L. Tolos , J. Schaffner-Bielich , S. Schramm

Precise and reliable measurements of the masses and radii of neutron stars with a variety of masses would provide valuable guidance for improving models of the properties of cold matter with densities above the saturation density of nuclear…

High Energy Astrophysical Phenomena · Physics 2016-04-20 M. Coleman Miller , Frederick K. Lamb

We combine equation of state of dense matter up to twice nuclear saturation density ($n_{\rm sat}=0.16\, \text{fm}^{-3}$) obtained using chiral effective field theory ($\chi$EFT), and recent observations of neutron stars to gain insights…

In this paper the impact of the strength of hyperon-nucleon and hyperon-hyperon on the maximum neutron star mass is shown. The strong hyperon-hyperon coupling constant together with the additional nonlinear meson interaction terms lead to…

Nuclear Theory · Physics 2008-11-26 Ilona Bednarek , Ryszard Manka

It is currently unknown how matter behaves at the extreme densities found within the cores of neutron stars. Measurements of the neutron star equation of state probe nuclear physics that is otherwise inaccessible in a laboratory setting.…

High Energy Astrophysical Phenomena · Physics 2026-03-03 Kris Walker , Rory Smith , Eric Thrane , Daniel J. Reardon

The equation of state (EoS) of neutron star (NS) matter is investigated considering kaon condensation. Moreover, the tidal parameters related to the components of binary neutron star mergers are determined and compared to the constraints of…

High Energy Astrophysical Phenomena · Physics 2021-12-21 Z. Sharifi , M. Bigdeli , D. Alvarez-Castillo , E. Nasiri

We carry out the study for finite nuclei, infinite nuclear matter and neutron star properties with the newly developed relativistic force named as the Institute Of Physics Bhubaneswar-I(IOPB-I). Using this force, we calculate the binding…

Nuclear Theory · Physics 2018-05-02 Bharat Kumar , S. K. Patra , B. K. Agrawal

Regarding a $d-$dimensional spherically symmetric line element in the context of Einstein-$\Lambda$ gravity, the hydrostatic equilibrium equation of stars is obtained. Then, by using the lowest order constrained variational (LOCV) method…

General Relativity and Quantum Cosmology · Physics 2017-01-30 G. H. Bordbar , S. H. Hendi , B. Eslam Panah

A reported ${17~}$MeV boson, which has been proposed as an explanation to the $^{8}$Be and $^{4}$He anomaly, is investigated in the context of its possible influence to neutron stars structure. Implementing a $m_{X}$=17 MeV to the nuclear…

High Energy Physics - Phenomenology · Physics 2021-07-09 Vlasios Petousis , Martin Veselsky , Jozef Leja

The minimum and maximum mass of protoneutron stars and neutron stars are investigated. The hot dense matter is described by relativistic (including hyperons) and non-relativistic equations of state. We show that the minimum mass ($\sim$…

Astrophysics · Physics 2011-05-23 Klaus Strobel , Manfred K. Weigel