scholarly journals The Effects of Nuclear Forces on the Maximum Mass Limit of Neutron Stars

1971 ◽  
Vol 46 ◽  
pp. 352-355
Author(s):  
Sachiko Tsuruta

The original models of neutron stars must be improved by including effects of nuclear interaction. This paper compares the models reached by various groups, and presents an improved model by the Kyoto group. The maximum mass varies between 0.2 M⊙ and 3 M⊙ in the various models. The Vγ model is recommended for use in the absence of further information on the equation of state at high densities.

1995 ◽  
Vol 04 (04) ◽  
pp. 531-548 ◽  
Author(s):  
E. DEL GIUDICE ◽  
R. MELE ◽  
G. PREPARATA ◽  
C. GUALDI ◽  
G. MANGANO ◽  
...  

In the framework of a novel approach to the dynamics of nuclei and large collections of nucleons, which fully exploits the coherent interaction among π’s, nucleons and Δ’s, we derive a new equation of state for neutronic matter. By introducing it in the Tolman-Oppenheimer-Volkof equations we derive the masses and radii of neutron stars as a function of the central density. We obtain a maximum mass Mmax≃2.7 Mʘ and a minimum period of rotation Tmin=0.8 msec.


2020 ◽  
Vol 29 (11) ◽  
pp. 2041015
Author(s):  
John L. Friedman ◽  
Nikolaos Stergioulas

The first inspiral of two neutron stars observed in gravitational waves was remarkably close, allowing the kind of simultaneous gravitational wave and electromagnetic observation that had not been expected for several years. Their merger, followed by a gamma-ray burst and a kilonova, was observed across the spectral bands of electromagnetic telescopes. These GW and electromagnetic observations have led to dramatic advances in understanding short gamma-ray bursts; determining the origin of the heaviest elements; and determining the maximum mass of neutron stars. From the imprint of tides on the gravitational waveforms and from observations of X-ray binaries, one can extract the radius and deformability of inspiraling neutron stars. Together, the radius, maximum mass, and causality constrain the neutron-star equation of state, and future constraints can come from observations of post-merger oscillations. We selectively review these results, filling in some of the physics with derivations and estimates.


2016 ◽  
Vol 463 (3) ◽  
pp. 2667-2679 ◽  
Author(s):  
A. M. Studzińska ◽  
M. Kucaba ◽  
D. Gondek-Rosińska ◽  
L. Villain ◽  
M. Ansorg

2015 ◽  
Vol 24 (01) ◽  
pp. 1550007 ◽  
Author(s):  
A. Sulaksono

We study the effects of anisotropic pressure (AI-P) on properties of the neutron stars (NSs) with hyperons inside its core within the framework of extended relativistic mean field. It is found that the main effects of AI-P on NS matter is to increase the stiffness of the equation of state EOS, which compensates for the softening of the EOS due to the hyperons. The maximum mass and redshift predictions of anisotropic neutron star with hyperonic core are quite compatible with the result of recent observational constraints if we use the parameter of AI-P model h ≤ 0.8 [L. Herrera and W. Barreto, Phys. Rev. D 88 (2013) 084022.] and Λ ≤ -1.15 [D. D. Doneva and S. S. Yazadjiev, Phys. Rev. D 85 (2012) 124023.]. The radius of the corresponding NS at M = 1.4 M⊙ is more than 13 km, while the effect of AI-P on the minimum mass of NS is insignificant. Furthermore, due to the AI-P in the NS, the maximum mass limit of higher than 2.1 M⊙ cannot rule out the presence of hyperons in the NS core.


2008 ◽  
Vol 23 (27n30) ◽  
pp. 2481-2484
Author(s):  
H. SHEN ◽  
F. YANG ◽  
P. YUE

We study the hadron-quark phase transition and antikaon condensation which may occur in the core of massive neutron stars. The relativistic mean field theory is used to describe the hadronic phase, while the Nambu-Jona-Lasinio model is adopted for the quark phase. We find that the hadron-quark phase transition is very sensitive to the models used. The appearance of deconfined quark matter and antikaon condensation can soften the equation of state at high density and lower the maximum mass of neutron stars.


2017 ◽  
Vol 95 (4) ◽  
Author(s):  
Hajime Sotani ◽  
Kostas D. Kokkotas

Symmetry ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1613
Author(s):  
Xavier Viñas ◽  
Claudia Gonzalez-Boquera ◽  
Mario Centelles ◽  
Chiranjib Mondal ◽  
Luis M. Robledo

The effective Gogny interactions of the D1 family were established by D. Gogny more than forty years ago with the aim to describe simultaneously the mean field and the pairing field corresponding to the nuclear interaction. The most popular Gogny parametrizations, namely D1S, D1N and D1M, describe accurately the ground-state properties of spherical and deformed finite nuclei all across the mass table obtained with Hartree–Fock–Bogoliubov (HFB) calculations. However, these forces produce a rather soft equation of state (EoS) in neutron matter, which leads to predict maximum masses of neutron stars well below the observed value of two solar masses. To remove this limitation, we built new Gogny parametrizations by modifying the density dependence of the symmetry energy predicted by the force in such a way that they can be applied to the neutron star domain and can also reproduce the properties of finite nuclei as good as their predecessors. These new parametrizations allow us to obtain stiffer EoS’s based on the Gogny interactions, which predict maximum masses of neutron stars around two solar masses. Moreover, other global properties of the star, such as the moment of inertia and the tidal deformability, are in harmony with those obtained with other well tested EoSs based on the SLy4 Skyrme force or the Barcelona–Catania–Paris–Madrid (BCPM) energy density functional. Properties of the core-crust transition predicted by these Gogny EoSs are also analyzed. Using these new Gogny forces, the EoS in the inner crust is obtained with the Wigner–Seitz approximation in the Variational Wigner–Kirkwood approach along with the Strutinsky integral method, which allows one to estimate in a perturbative way the proton shell and pairing corrections. For the outer crust, the EoS is determined basically by the nuclear masses, which are taken from the experiments, wherever they are available, or by HFB calculations performed with these new forces if the experimental masses are not known.


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