Symmetry energy, unstable nuclei and neutron star crusts

2014 ◽  
Vol 50 (2) ◽  
Author(s):  
Kei Iida ◽  
Kazuhiro Oyamatsu
Universe ◽  
2020 ◽  
Vol 6 (8) ◽  
pp. 119 ◽  
Author(s):  
G. Fiorella Burgio ◽  
Isaac Vidaña

Background. We investigate possible correlations between neutron star observables and properties of atomic nuclei. In particular, we explore how the tidal deformability of a 1.4 solar mass neutron star, M1.4, and the neutron-skin thickness of 48Ca and 208Pb are related to the stellar radius and the stiffness of the symmetry energy. Methods. We examine a large set of nuclear equations of state based on phenomenological models (Skyrme, NLWM, DDM) and ab initio theoretical methods (BBG, Dirac–Brueckner, Variational, Quantum Monte Carlo). Results: We find strong correlations between tidal deformability and NS radius, whereas a weaker correlation does exist with the stiffness of the symmetry energy. Regarding the neutron-skin thickness, weak correlations appear both with the stiffness of the symmetry energy, and the radius of a M1.4. Our results show that whereas the considered EoS are compatible with the largest masses observed up to now, only five microscopic models and four Skyrme forces are simultaneously compatible with the present constraints on L and the PREX experimental data on the 208Pb neutron-skin thickness. We find that all the NLWM and DDM models and the majority of the Skyrme forces are excluded by these two experimental constraints, and that the analysis of the data collected by the NICER mission excludes most of the NLWM considered. Conclusion. The tidal deformability of a M1.4 and the neutron-skin thickness of atomic nuclei show some degree of correlation with nuclear and astrophysical observables, which however depends on the ensemble of adopted EoS.


2011 ◽  
Vol 84 (3) ◽  
Author(s):  
Chung-Yeol Ryu ◽  
Chang Ho Hyun ◽  
Chang-Hwan Lee

2014 ◽  
Vol 50 (2) ◽  
Author(s):  
S. Gandolfi ◽  
J. Carlson ◽  
S. Reddy ◽  
A. W. Steiner ◽  
R. B. Wiringa

2019 ◽  
Vol 26 ◽  
pp. 120
Author(s):  
Ch. Margaritis ◽  
L. Tsaloukidis ◽  
Ch. C. Moustakidis

We systematically  study the symmetry energy  effects of the transition  density ntand the transition pressure Ptaround the crust-core interface of a neutron star in the framework of the dynamical and the thermodynamical method respectively. We employ both the parabolic approximation and the full expansion, for the definition of the symmetry energy. We use various theoretical  nuclear models. Firstly we derive and present an approximation for the transition pressure Ptand crustal mass Mcrust. Secondly, we explore the effects of the Equation of State (EoS) on a few astrophysical applications which are sensitive to the values of n­tand Pt. We found that the above quantities are sensitive mainly on the applied approximation for the symmetry energy (confirming previous results). Furthermore, an additional sensitivity also exists, depending on the used method (dynamical or thermodynamical). The above findings lead us to claim that the determination of the n­tand Ptmust be reliable and accurate before they are used to constrain relevant neutron star properties.


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