scholarly journals A Modern View of the Equation of State in Nuclear and Neutron Star Matter

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 400
Author(s):  
G. Fiorella Burgio ◽  
Hans-Josef Schulze ◽  
Isaac Vidaña ◽  
Jin-Biao Wei
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Nuclear Matter ◽  
Symmetry Energy ◽  
Quantum Monte Carlo ◽  
Mean Field ◽  
Nuclear Symmetry Energy ◽  
Relativistic Mean Field ◽  
Monte Carlo Techniques ◽  
Nuclear Incompressibility

Background: We analyze several constraints on the nuclear equation of state (EOS) currently available from neutron star (NS) observations and laboratory experiments and study the existence of possible correlations among properties of nuclear matter at saturation density with NS observables. Methods: We use a set of different models that include several phenomenological EOSs based on Skyrme and relativistic mean field models as well as microscopic calculations based on different many-body approaches, i.e., the (Dirac–)Brueckner–Hartree–Fock theories, Quantum Monte Carlo techniques, and the variational method. Results: We find that almost all the models considered are compatible with the laboratory constraints of the nuclear matter properties as well as with the largest NS mass observed up to now, 2.14−0.09+0.10M⊙ for the object PSR J0740+6620, and with the upper limit of the maximum mass of about 2.3–2.5M⊙ deduced from the analysis of the GW170817 NS merger event. Conclusion: Our study shows that whereas no correlation exists between the tidal deformability and the value of the nuclear symmetry energy at saturation for any value of the NS mass, very weak correlations seem to exist with the derivative of the nuclear symmetry energy and with the nuclear incompressibility.

scholarly journals Nucleon properties inside the compressed nuclear matter

2018 ◽  
Vol 27 (04) ◽  
pp. 1850030
Author(s):  
Jacek Rożynek
Keyword(s):  
Energy Transfer ◽  
Equation Of State ◽  
Nuclear Matter ◽  
Symmetry Energy ◽  
Mean Field ◽  
Equilibrium Density ◽  
Nucleon Mass ◽  
Relativistic Mean Field ◽  
Rmf Model

In this work, we show the modifications of nucleon mass and nucleon radius with the help of the extended Relativistic Mean Field (RMF) model. We argue that even small departures above nuclear equilibrium density with constant nucleon mass require an energy transfer from the repulsive mean field to the quarks forming nucleon massive bags in Nuclear Matter (NM), together with the decrease in the nucleon volume. The transfer, which is proportional to pressure and absent in a standard RMF approach, provides good values for nuclear compressibility, symmetry energy and its slope. Different courses of the Equation of State (EOS), which depend on the energy transfer, are considered.

scholarly journals Nuclear symmetry energy in relativistic mean field theory

2006 ◽  
Vol 633 (2-3) ◽  
pp. 231-236 ◽  
Author(s):  
Shufang Ban ◽  
Jie Meng ◽  
Wojciech Satuła ◽  
Ramon A. Wyss
Keyword(s):  
Field Theory ◽  
Symmetry Energy ◽  
Mean Field Theory ◽  
Mean Field ◽  
Nuclear Symmetry Energy ◽  
Relativistic Mean Field Theory ◽  
Relativistic Mean Field

scholarly journals THE MICROSCOPIC APPROACH TO NUCLEAR MATTER AND NEUTRON STAR MATTER

2010 ◽  
Vol 19 (07) ◽  
pp. 1259-1313 ◽  
Author(s):  
FRANCESCA SAMMARRUCA
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Nuclear Matter ◽  
Symmetry Energy ◽  
Heavy Ion ◽  
Experimental Investigations ◽  
Common Denominator ◽  
Neutron Skin ◽  
Microscopic Approach ◽  
Ion Collisions

We review a variety of theoretical and experimental investigations aimed at improving our knowledge of the nuclear matter equation of state. Of particular interest are nuclear matter extreme states in terms of density and/or isospin asymmetry. The equation of state of matter with unequal concentrations of protons and neutrons has numerous applications. These include heavy-ion collisions, the physics of rare, short-lived nuclei and, on a dramatically different scale, the physics of neutron stars. The "common denominator" among these (seemingly) very different systems is the symmetry energy, which plays a crucial role in both the formation of the neutron skin in neutron-rich nuclei and the radius of a neutron star (a system 18 orders of magnitude larger and 55 orders of magnitudes heavier). The details of the density dependence of the symmetry energy are not yet sufficiently constrained. Throughout this article, our emphasis will be on the importance of adopting a microscopic approach to the many-body problem, which we believe to be the one with true predictive power.

NEUTRON STAR MASS CORRELATION WITH SOUND VELOCITY AND INCOMPRESSIBILITY AT THE STAR CENTER IN THE POLYTROPIC APPROXIMATION

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1575-1582
Author(s):  
L. FERRARI ◽  
P. C. R. ROSSI ◽  
M. MALHEIRO
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Nuclear Matter ◽  
Sound Velocity ◽  
Mean Field ◽  
Star Mass ◽  
Mean Field Models ◽  
Neutron Star Mass ◽  
Analytic Expressions ◽  
Walecka Model

In this paper we use a polytropic approximation to the equation of state for the interior of neutrons stars, described by relativistic hadronic mean field models. In this approximation, it is possible to obtain analytic expressions for the sound velocity and the incompressibility at the star center. We found a correlation between these quantities and the star mass. Using two well-known parametrizations of the nonlinear Walecka model for nuclear matter composed only of protons, neutrons and electron in β equilibrium, we obtain for a star mass of 1.43 M⊙ a central incompressibility Kc = (3000±100), around ten times the nuclear matter incompressibility, and a central sound velocity (v/c)2 ~ 0.3.

THE NUCLEON STRUCTURE AND THE EQUATION OF STATE FOR NUCLEAR MATTER

2007 ◽  
Vol 16 (02) ◽  
pp. 608-615
Author(s):  
J. ROŻYNEK
Keyword(s):  
Equation Of State ◽  
Structure Function ◽  
Nuclear Matter ◽  
Mean Field ◽  
Nucleon Structure ◽  
Final State ◽  
Rest Energy ◽  
Relativistic Mean Field ◽  
Quark Contribution ◽  
Nucleon Structure Function

We show the density dependent corrections to the nucleon structure function in the frame of nuclear Relativistic Mean Field (RMF) models. These corrections are connected with the modifications of the parton distribution in nuclei emerging from generalized nuclear Fermi motion and final state interactions between the nucleon and the rest of the nucleus. The medium effects concern the nucleon structure, namely the changes in the nucleon rest energy, the enhancement of sea quark contribution (simulated with "nuclear pions") and the modifications of the transverse parton momentum distribution inside Nuclear Matter (NM). The sea parton distributions are described by the modified cloud of virtual pions in order to saturate the nuclear energy-momentum sum rule. The description of theses features are in good agreement with experimental data; the EMC effect for x > 0.15 and nuclear lepton pair production data has been described essentialy without free parameters. The influence of these medium modifications to the nucleon structure function within the equation of state in RMF models of NM will be discussed.

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 Merging neutron star binaries: equation of state and electrodynamics

2012 ◽  
Vol 8 (S291) ◽  
pp. 149-154
Author(s):  
Dong Lai
Keyword(s):  
Neutron Star ◽  
Equation Of State ◽  
Gravitational Wave ◽  
Electromagnetic Radiation ◽  
Symmetry Energy ◽  
Fast Imaging ◽  
Wide Field ◽  
Nuclear Symmetry Energy ◽  
Imaging Telescopes

AbstractMerging neutron star (NS) binaries may be detected by ground-based gravitational wave (GW) interferometers (e.g. LIGO/VIRGO) within this decade and may also generate electromagnetic radiation detectable by wide-field, fast imaging telescopes that are coming online. The GWs can provide new constraint on the NS equation of state (including mass-radius relation and the related nuclear symmetry energy). This paper reviews various hydrodynamical and electrodynamical processes in coalescing NS binaries, with focus on the pre-merger phase.

Sign in / Sign up

Export Citation Format

Share Document