scholarly journals Recent Progress in Neutron Star Theory

2000 ◽  
Vol 50 (1) ◽  
pp. 481-524 ◽  
Author(s):  
Henning Heiselberg ◽  
Vijay Pandharipande

▪ Abstract  We review recent progress in the theory of neutron stars and compare its predictions with the observational data on masses, radii, and temperatures. The theory of neutron stars made up of neutrons, protons, and leptons is discussed in detail along with recent models of nuclear forces and modern many-body techniques. The possibilities of pion and kaon condensation in dense neutron star matter are considered, as is the possible occurrence of strange hyperons and quark-matter drops in the stellar core. The structure of mixed-phase matter in neutron stars, as well as the probable effect of phase transitions on the spin down of pulsars, is also discussed.

1974 ◽  
Vol 53 ◽  
pp. 133-150 ◽  
Author(s):  
V. Canuto ◽  
S. M. Chitre

Using the many-body techniques appropriate for quantum crystals it is shown that the deep interior of a neutron star is most likely an orderly arrangement of neutrons, protons and hyperons forming a solid. It is shown that a liquid or gas arrangement would produce higher energy. If so, a neutron star can be viewed as two solids (crust and core) permeated by a layer of ordinary or (perhaps) superfluid liquid. Astronomical evidence is in favor of such a structure: the sudden jumps in the periods of the Crab and Vela pulsars that differ by a factor of ∼ 102 can be easily explained by the star-quake model. If the Crab is less massive than Vela (i.e., if it is not dense enough to have a solid core), the star-quakes take place in the crust whereas for Vela they occur in the core.


2013 ◽  
Vol 22 (05) ◽  
pp. 1350026 ◽  
Author(s):  
CHEN WU ◽  
WEI-LIANG QIAN ◽  
YU-GANG MA ◽  
JI-FENG YANG

Relativistic mean-field theory with parameter sets FSUGold and IU-FSU is extended to study the properties of neutron star matter in β equilibrium by including Kaon condensation. The mixed phase of normal baryons and Kaon condensation cannot exist in neutron star matter for the FSUGold model and the IU-FSU model. In addition, it is found that when the optical potential of the K- in normal nuclear matter UK ≳ -100 MeV , the Kaon condensation phase is absent in the inner cores of the neutron stars.


2007 ◽  
Vol 75 (6) ◽  
Author(s):  
C. Ducoin ◽  
K. H. O. Hasnaoui ◽  
P. Napolitani ◽  
Ph. Chomaz ◽  
F. Gulminelli

1971 ◽  
Vol 46 ◽  
pp. 356-363
Author(s):  
M. R. McNaughton

The conditions for superfluidity or ferromagnetism in neutron stars are presented and discussed (but not derived). It is suggested that present estimates relating to these are in error and that the predictions made contradict at least one of three sets of nuclear physics data cited in the text. This is due to neglecting the action of the exclusion principle.A comparatively simple method for calculating the strength of nuclear forces in the presence of many-body effects is outlined. Some preliminary results are presented together with projected future developments.


1992 ◽  
Vol 291 (4) ◽  
pp. 355-362 ◽  
Author(s):  
G.E. Brown ◽  
Kuniharu Kubodera ◽  
Mannque Rho ◽  
Vesteinn Thorsson

Universe ◽  
2019 ◽  
Vol 5 (10) ◽  
pp. 204 ◽  
Author(s):  
Domenico Logoteta ◽  
Ignazio Bombaci

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.


1974 ◽  
Vol 29 (6) ◽  
pp. 933-946
Author(s):  
H. Heintzmann ◽  
W. Hillebrandt ◽  
M. F. El Eid ◽  
E. R. Hilf

Various methods to study the ground state of neutron star matter are compared and the corresponding neutron star models are contrasted with each other. In the low density region ρ < 1014gr cm-3 the nuclear gas is treated here by means of a Thomas Fermi method and the nuclei are described by the droplet model of Myers and Swiatecki. For ρ > 1014 gr cm-3 both standard Brueckner theory with more realistic interaction (one-boson-exchange) potentials and the semiphenomenological theory of Fermi liquids (together with the standard Reid softcore potential) are applied to neutron star matter. It is shown that while the high mass limit of neutron stars is hardly affected, some properties of lowmass neutron stars such as their binding depend sensitively on these refinements. Various tentative (but unreliable) extensions of the equation of state into high density regime ρ > 1015 gr cm-3 are investigated and it is shown that the mass limit for heavy neutron stars lies around 2.5 solar masses. It is further shown that a third family of stable (hyperon) stars is not forbidden by general relativistic arguments if there is a phase transition at high densities.


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