THE INNER CRUST OF NEUTRON STARS IN RELATIVISTIC MEAN FIELD APPROACH

2008 ◽  
Vol 17 (09) ◽  
pp. 1765-1773 ◽  
Author(s):  
JIGUANG CAO ◽  
ZHONGYU MA ◽  
NGUYEN VAN GIAI
Keyword(s):  
Boundary Conditions ◽  
Neutron Stars ◽  
Mean Field ◽  
Bcs Theory ◽  
Neutron Density ◽  
Field Approach ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Density Distributions ◽  
Rmf Model

The microscopic properties and superfluidity of the inner crust in neutron stars are investigated in the framework of the relativistic mean field(RMF) model and BCS theory. The Wigner-Seitz(W-S) cell of inner crust is composed of neutron-rich nuclei immersed in a sea of dilute, homogeneous neutron gas. The pairing properties of nucleons in the W-S cells are treated in BCS theory with Gogny interaction. In this work, we emphasize on the choice of the boundary conditions in the RMF approach and superfluidity of the inner crust. Three kinds of boundary conditions are suggested. The properties of the W-S cells with the three kinds of boundary conditions are investigated. The neutron density distributions in the RMF and Hartree-Fock-Bogoliubov(HFB) models are compared.

scholarly journals Constraints on Microscopic and Phenomenological Equations of State of Dense Matter from GW170817

Universe ◽  
2019 ◽  
Vol 5 (10) ◽  
pp. 204 ◽  
Author(s):  
Domenico Logoteta ◽  
Ignazio Bombaci
Keyword(s):  
Neutron Star ◽  
Neutron Stars ◽  
Equations Of State ◽  
Mean Field ◽  
Dense Matter ◽  
Neutron Star Matter ◽  
Field Approach ◽  
Relativistic Mean Field ◽  
Three Body ◽  
Good Agreement

We discuss the constraints on the equation of state (EOS) of neutron star matter obtained by the data analysis of the neutron star-neutron star merger in the event GW170807. To this scope, we consider two recent microscopic EOS models computed starting from two-body and three-body nuclear interactions derived using chiral perturbation theory. For comparison, we also use three representative phenomenological EOS models derived within the relativistic mean field approach. For each model, we determine the β -stable EOS and then the corresponding neutron star structure by solving the equations of hydrostatic equilibrium in general relativity. In addition, we calculate the tidal deformability parameters for the two neutron stars and discuss the results of our calculations in connection with the constraints obtained from the gravitational wave signal in GW170817. We find that the tidal deformabilities and radii for the binary’s component neutron stars in GW170817, calculated using a recent microscopic EOS model proposed by the present authors, are in very good agreement with those derived by gravitational waves data.

HYPERON DENSITY DEPENDENCE OF HYPERON-NUCLEON INTERACTIONS IN NEUTRON STARS

2008 ◽  
Vol 17 (09) ◽  
pp. 1720-1728
Author(s):  
L. DANG ◽  
P. YUE ◽  
L. LI ◽  
P. Z. NING
Keyword(s):  
Equation Of State ◽  
Neutron Stars ◽  
Density Dependence ◽  
Mean Field ◽  
Density Dependent ◽  
Effective Potentials ◽  
Relativistic Mean Field ◽  
Nucleon Interactions ◽  
Dependent Factor ◽  
Rmf Model

The hyperon density dependence (YDD) of hyperon-nucleon interactions are studied in the relativistic mean field (RMF) model and their influences on the properties of neutron stars are studied. The extended RMF considered the interior quarks coordinates of hyperon and bring a hyperon density dependent factor, f(ρY), to the meson-hyperon coupling vertexes. The hyperon density dependence of YN interaction affect the properties of neutron stars only after the corresponding hyperon appears. Then, the influences of the density dependence factors are almost ignored at low densities, which are clear at high densities. The compositions and properties of neutron stars are studied with and without the YDD of YN interactions for the different Σ--nucleus effective potentials, (30, 0, -30)MeV. The calculated results indicated that the YDD of YN interaction soften the equation of state of neutron stars at high densities.

SIGNATURES OF ISOVECTOR COMPONENTS OF THE SCALAR σ-MESON IN NEUTRON STARS

2004 ◽  
Vol 13 (07) ◽  
pp. 1255-1259 ◽  
Author(s):  
EDUARDO LÜTZ ◽  
MOISÉS RAZEIRA ◽  
CÉSAR A. Z. VASCONCELLOS ◽  
MANFRED DILLIG
Keyword(s):  
Neutron Star ◽  
Scalar Field ◽  
Neutron Stars ◽  
Mean Field ◽  
Hadronic Matter ◽  
Field Approach ◽  
Relativistic Mean Field ◽  
Intermediate States

Based on non-crossed, crossed and correlated ππ exchanges with irreducible N, Δ intermediate states, we predict an isovector component for the σ meson. We study dense hadronic matter in a generalized relativistic mean field approach with nonlinear self-couplings of the I=0,1 components of the scalar field and compare its predictions for neutron star properties with results from different models found in the literature.

NEW CALCULATION FOR SOME GROUND STATE FEATURES OF 40Ca, 48Ca32S AND 39K NUCLEI

2010 ◽  
Vol 19 (02) ◽  
pp. 291-298 ◽  
Author(s):  
H. AYTEKIN ◽  
R. BALDIK ◽  
E. TEL ◽  
A. AYDIN
Keyword(s):  
Ground State ◽  
Nuclear Charge ◽  
Mean Field ◽  
Binding Energies ◽  
Charge Radii ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Density Distributions ◽  
Total Binding ◽  
Experimental Values

Some ground states features of 32 S , 39 K , 40 Ca and 48 Ca nuclei are investigated using the Hartree–Fock method with the Skyrme SKM * and SLy4 forces calculated in two different code implementations. The calculated total binding energies per particle and root mean square (rms) nuclear charge radii using the Skyrme–Hartree–Fock (SHF) + BCS method are compared with relativistic mean-field (RMF) theory and experimental values. The obtained charge density distributions from these code implementations are compared with the experimental data. Pairing effects are also included in calculations for the same nuclei. Variations of the total binding energies per particle and rms nuclear charge radii were investigated as the last shell nucleons were carried to the upper shell.

Asymmetric neutrino production in magnetized proto-neutron stars in fully relativistic mean-field approach

2014 ◽  
Author(s):  
Tomoyuki Maruyama ◽  
Toshitaka Kajino ◽  
Nobutoshi Yasutake ◽  
Jun Hidaka ◽  
Takami Kuroda ◽  
...  
Keyword(s):  
Neutron Stars ◽  
Mean Field ◽  
Field Approach ◽  
Relativistic Mean Field ◽  
Neutrino Production

NONLINEAR σ, δ DERIVATIVE SELF-COUPLINGS IN A RMFT FOR NEUTRON STARS

2004 ◽  
Vol 13 (07) ◽  
pp. 1485-1491 ◽  
Author(s):  
SÉRGIO S. ROCHA ◽  
MOISÉS RAZEIRA ◽  
CÉSAR A. Z. VASCONCELLOS ◽  
MANFRED DILLIG
Keyword(s):  
Neutron Stars ◽  
Nuclear Matter ◽  
Mean Field ◽  
Hadronic Matter ◽  
Field Approach ◽  
Relativistic Mean Field ◽  
Global Properties ◽  
Substantial Modification ◽  
Nonlinear Couplings

We study dense hadronic matter in a generalized relativistic mean field approach which contains nonlinear couplings of the σ, ω, ϱ, δ fields and compare its predictions for properties of neutron stars with the corresponding results from different models found in the literature. Our predictions indicate a substantial modification in static global properties of nuclear matter and neutron stars with the inclusion of the δ meson into the formalism.

Skyrme–Hartree–Fock–Bogoliubov Calculations of Even and Odd Neutron-Rich Mg Isotopes

2021 ◽  
Vol 66 (11) ◽  
pp. 928
Author(s):  
A.H. Taqi ◽  
M.A. Hasan
Keyword(s):  
Experimental Data ◽  
Mean Field ◽  
Field Method ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Nuclear Models ◽  
Quadrupole Deformation Parameter ◽  
Mg Isotopes ◽  
The One ◽  
Rmf Model

Using the Skyrme functional with SIII, SKM*, SLy4, and UNE0 sets of parameters and the Hartree–Fock–Bogoliubov mean-field method; the ground-state properties of even-even and even-odd neutron-rich Mg isotopes have been investigated. The results of calculations of the binding energy per nucleon (B/A), the one- and two-neutron separation energies (Sn and S2n), proton and neutron rms radii, neutron pairing gap, and quadrupole deformation parameter (B2) have been compared with the available experimental data, the results of Hartree–Fock–Bogoliubov calculations based on the D1S Gogny force, and predictions of some nuclear models such as the Finite Range Droplet Model (FRDM) and Relativistic Mean-Field (RMF) model. Our results show good agreements in comparison with the experimental data and the results of the mentioned models.

scholarly journals ENERGY SYSTEMATICS OF HEAVY NUCLEI — MEAN FIELD MODELS IN COMPARISON

2011 ◽  
Vol 20 (06) ◽  
pp. 1379-1390 ◽  
Author(s):  
P.-G. REINHARD ◽  
B. K. AGRAWAL
Keyword(s):  
Mean Field ◽  
Binding Energies ◽  
Superheavy Nuclei ◽  
Heavy Nuclei ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Mean Field Models ◽  
Opposite Trend ◽  
Super Heavy Nuclei ◽  
Rmf Model

We compare the systematics of binding energies computed within the standard and extended versions of the relativistic mean-field (RMF) model and the Skyrme–Hartree–Fock (SHF) model. The general trends for the binding energies for super-heavy nuclei are significantly different for these models. The SHF models tend to underbind the superheavy nuclei, while RMF models show just the opposite trend. The extended RMF model seems to provide remarkable improvements over the results obtained for the standard RMF model.

scholarly journals Relativistic density functional for nuclear matter

2019 ◽  
Vol 204 ◽  
pp. 05001
Author(s):  
Stefan Gmuca ◽  
Kristian Petrík ◽  
Jozef Leja
Keyword(s):  
Energy Density ◽  
Nuclear Matter ◽  
Density Functional ◽  
Mean Field ◽  
Dense Matter ◽  
Coupling Constants ◽  
Effective Coupling ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Rmf Model

In the present work, we have mapped the exchange Fock contributions from the Dirac–Hartree–Fock (DHF) approach for nuclear matter onto the direct Hartree terms. This results in the relativistic mean field (RMF) model with the density dependent couplings. The density dependence of the effective coupling constants thus reflects the exchange correlations. The exchange part of an energy density of the linear DHF model in dense matter is evaluated in a parameter-free closed form and, after the rearrangement of the terms, expressed as density functional.

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