EFFECTS OF THE NUCLEAR SYMMETRY ENERGY ON GRAVITATIONAL WAVES FROM THE AXIAL W-MODES OF ISOLATED NEUTRON STARS

2010 ◽  
Vol 19 (08n09) ◽  
pp. 1712-1719
Author(s):  
DE-HUA WEN ◽  
BAO-AN LI ◽  
PLAMEN G. KRASTEV
Keyword(s):  
Equation Of State ◽  
Neutron Stars ◽  
Gravitational Waves ◽  
Symmetry Energy ◽  
Laboratory Data ◽  
High Density ◽  
Nuclear Symmetry Energy ◽  
Nuclear Equation Of State ◽  
Eigen Frequencies ◽  
Density Behavior

The frequencies and damping times of the axial w-mode oscillations of neutron stars are investigated using a nuclear equation of state (EOS) partially constrained by the available terrestrial laboratory data. It is found that the nuclear symmetry energy E sym (ρ), especially its high density behavior, plays an important role in determining both the eigen-frequencies and the damping times of these oscillations.

scholarly journals Density dependence of nuclear symmetry energy

2016 ◽  
Vol 31 (34) ◽  
pp. 1650194 ◽  
Author(s):  
B. Behera ◽  
T. R. Routray ◽  
S. K. Tripathy
Keyword(s):  
Neutron Stars ◽  
Density Dependence ◽  
Symmetry Energy ◽  
High Density ◽  
Nuclear Symmetry Energy ◽  
Density Behavior

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.

scholarly journals KIDS Energy Density Functional and Mass–Radius Relation of Neutron Stars

2019 ◽  
Vol 26 ◽  
pp. 112
Author(s):  
G. Ahn ◽  
P. Papakonstantinou
Keyword(s):  
Equation Of State ◽  
Energy Density ◽  
Neutron Stars ◽  
Symmetry Energy ◽  
Density Functional ◽  
Nuclear Symmetry Energy ◽  
Unified Framework ◽  
Energy Density Functional ◽  
Nuclear Equation Of State ◽  
Derivatives Of

Many efforts are made to determine the nuclear equation of state which governs the properties and evolution of neutron stars. Especially important is to constrain the parameters of the nuclear symmetry energy. In those efforts, nuclear energy density functional (EDF) theory has been a very useful tool, as it provides a unified framework for the description both of nuclei, which can be studied on Earth, and of infinite matter and its nuclear equation of state, which is a necessary input in the modelling of neutron stars. In the present study, a new nuclear EDF, the KIDS functional, is explored with a focus on the nuclear symmetry energy. The form of the functional allows us to vary at will the poorly constrained high-order derivatives of the symmetry energy and examine how the maximum possible mass of a neutron star is affected. Some tentative constraints on the skewness are presented, which will help guide further refinements. It is noteworthy that the pressure of neutron-rich matter is found strongly affected by skewness variations, both at low and high densities.

scholarly journals Nuclear equation of state constraints from tidal deformability of neutron stars

2019 ◽  
Vol 21 ◽  
pp. 44
Author(s):  
Ch. C. Moustakidis
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Symmetry Energy ◽  
State Constraints ◽  
Equations Of State ◽  
Recent Observation ◽  
Nuclear Symmetry Energy ◽  
Nuclear Equation Of State ◽  
Theoretical Predictions

We study the effect of nuclear equation of state on the tidal polarizability of neutron stars. The predicted equations of state for the β-stable nuclear matter are parameterized by varying the slope L of the symmetry energy at saturation density on the interval 65 MeV≤L≤115 MeV. The effects of the density dependence of the nuclear symmetry energy on the neutron star tidal polarizability are presented and analyzed. A comparison of theoretical predictions with the recent observation predictions is also performed and analyzed.

scholarly journals Chiral Effective Field Theory and the High-Density Nuclear Equation of State

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
C. Drischler ◽  
J.W. Holt ◽  
C. Wellenhofer
Keyword(s):  
Field Theory ◽  
Equation Of State ◽  
Neutron Stars ◽  
Nuclear Matter ◽  
Effective Field Theory ◽  
Effective Field ◽  
High Density ◽  
Chiral Effective Field Theory ◽  
Nuclear Equation Of State ◽  
Density Regime

Born in the aftermath of core-collapse supernovae, neutron stars contain matter under extraordinary conditions of density and temperature that are difficult to reproduce in the laboratory. In recent years, neutron star observations have begun to yield novel insights into the nature of strongly interacting matter in the high-density regime where current theoretical models are challenged. At the same time, chiral effective field theory has developed into a powerful framework to study nuclear matter properties with quantified uncertainties in the moderate-density regime for modeling neutron stars. In this article, we review recent developments in chiral effective field theory and focus on many-body perturbation theory as a computationally efficient tool for calculating the properties of hot and dense nuclear matter. We also demonstrate how effective field theory enables statistically meaningful comparisons among nuclear theory predictions, nuclear experiments, and observational constraints on the nuclear equation of state. Expected final online publication date for the Annual Review of Nuclear and Particle Science, Volume 71 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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