scholarly journals Interplay between the symmetry energy and the strangeness content of neutron stars

2013 ◽  
Vol 87 (5) ◽  
Author(s):  
Constança Providência ◽  
Aziz Rabhi
2014 ◽  
Vol 50 (2) ◽  
Author(s):  
Constança Providência ◽  
Sidney S. Avancini ◽  
Rafael Cavagnoli ◽  
Silvia Chiacchiera ◽  
Camille Ducoin ◽  
...  

2020 ◽  
Vol 15 ◽  
pp. 196
Author(s):  
T. Gaitanos ◽  
G. Ferini ◽  
M. Colonna ◽  
M. Di Toro ◽  
G. A. Lalazissis ◽  
...  

We present several possibilities offered by nuclear structure, the dynamics of intermediate energy heavy ion collisions and neutron stars to investigate the nuclear matter equation of state (EoS) beyond the ground state. In particular the high density nuclear EoS of asymmetric matter, i.e. the symmetry energy, is discussed.


Author(s):  
Jinniu Hu ◽  
Shishao Bao ◽  
Ying Zhang ◽  
Ken’ichiro Nakazato ◽  
Kohsuke Sumiyoshi ◽  
...  

Abstract The radii and tidal deformabilities of neutron stars are investigated in the framework of the relativistic mean-field (RMF) model with different density-dependent behaviors of symmetry energy. To study the effects of symmetry energy on the properties of neutron stars, $\omega$ meson and $\rho$ meson coupling terms are included in a popular RMF Lagrangian, i.e., the TM1 parameter set, which is adopted for the widely used supernova equation of state (EoS) table. The coupling constants relevant to the vector–isovector meson, $\rho$, are refitted by a fixed symmetry energy at subsaturation density and its slope at saturation density, while other coupling constants remain the same as the original ones in TM1 so as to update the supernova EoS table. The radius and mass of maximum neutron stars are not so sensitive to the symmetry energy in these family TM1 parameterizations. However, the radii in the intermediate-mass region are strongly correlated with the slope of symmetry energy. Furthermore, the dimensionless tidal deformabilities of neutron stars are also calculated within the associated Love number, which is related to the quadrupole deformation of the star in a static external tidal field and can be extracted from the observation of a gravitational wave generated by a binary star merger. We find that its value at $1.4 \mathrm{M}_\odot$ has a linear correlation to the slope of symmetry energy, unlike that previously studied. With the latest constraints of tidal deformabilities from the GW170817 event, the slope of symmetry energy at nuclear saturation density should be smaller than $60$ MeV in the family TM1 parameterizations. This fact supports the usage of a lower symmetry energy slope for the updated supernova EoS, which is applicable to simulations of neutron star mergers. Furthermore, an analogous analysis is also done within the family IUFSU parameter sets. It is found that the correlations between the symmetry energy slope with the radius and tidal deformability at $1.4 \mathrm{M}_\odot$ have very similar linear relations in these RMF models.


2014 ◽  
Vol 335 (6-7) ◽  
pp. 739-744
Author(s):  
M. Razeira ◽  
A. Mesquita ◽  
C.A.Z. Vasconcellos ◽  
R. Ruffini ◽  
J.A. Rueda ◽  
...  

2016 ◽  
Vol 31 (34) ◽  
pp. 1650194 ◽  
Author(s):  
B. Behera ◽  
T. R. Routray ◽  
S. K. Tripathy

High density behavior of nuclear symmetry energy is studied on the basis of the stiffest density dependence of asymmetric contribution to energy per nucleon in charge neutral n + p + e + [Formula: see text] matter under beta equilibrium. The density dependence of nuclear symmetry energy obtained in this way is neither very stiff nor soft at high densities and is found to be in conformity with recent observations of neutron stars.


2020 ◽  
Vol 229 (22-23) ◽  
pp. 3615-3628
Author(s):  
David Alvarez-Castillo ◽  
Alexander Ayriyan ◽  
Gergely Gábor Barnaföldi ◽  
Hovik Grigorian ◽  
Péter Pósfay

AbstractIn this work we study the parameters of the extended σ-ω model for neutron star matter by a Bayesian analysis of state-of-the-art multi-messenger astronomy observations, namely mass, radius and tidal deformabilities. We have considered three parameters of the model, the Landau mass mL, the nuclear compressibility K0, and the value of the symmetry energy S0, all at saturation density n0. As a result, we are able to estimate the best values of the Landau mass of mL ≈ 0.73 GeV, whereas the values of K0 and S0 fall within already known empirical values. Furthermore, for neutron stars we find the most probable value of 13 km < R1.4 < 13.5 km and the upper mass limit of Mmax ≈ 2.2 M⊙.


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