scholarly journals Examination of the influence of thef0(975)andϕ(1020) mesons on the surface gravitational redshift of the neutron star PSR J0348+0432

2015 ◽  
Vol 92 (5) ◽  
Author(s):  
Xian-Feng Zhao
Keyword(s):  
Neutron Star ◽  
Gravitational Redshift

scholarly journals Observational Constraints on the Surface Gravitational Redshift of a Neutron Star

2017 ◽  
Author(s):  
Masachika Iwai ◽  
Tadayasu Dotani ◽  
Masanobu Ozaki ◽  
Yoshitomo Maeda ◽  
Hideyuki Mori ◽  
...  
Keyword(s):  
Neutron Star ◽  
Gravitational Redshift ◽  
Observational Constraints

scholarly journals Double dark matter admixed neutron star

2018 ◽  
Vol 27 (16) ◽  
pp. 1950002 ◽  
Author(s):  
Zeinab Rezaei
Keyword(s):  
Dark Matter ◽  
Neutron Star ◽  
Equation Of State ◽  
Neutron Stars ◽  
Equations Of State ◽  
Compact Object ◽  
Gravitational Redshift ◽  
Two Fluid

The dark matter (DM) in neutron stars can exist from the lifetime of the progenitor or when captured by this compact object. The properties of DM that enter the neutron stars through each step could be different from each other. Here, we investigate the structure of neutron stars which are influenced by the DM in two processes. Applying a generalization of two-fluid formalism to three-fluid one and the equation-of-state from the rotational curves of galaxies, we explore the structure of double DM admixed neutron stars. The behavior of the neutron and DM portions for these stars is considered. In addition, the influence of the DM equations of state on the stars with different contributions of visible and DM are studied. The gravitational redshift of these stars in different cases of DM equations of state is investigated.

scholarly journals About Bonnor Solution and Gravitational Redshift

2017 ◽  
Vol 45 ◽  
pp. 1760048
Author(s):  
Orlenys Troconis ◽  
Viviane Alfradique ◽  
Rodrigo Negreiros
Keyword(s):  
Dipole Moment ◽  
Neutron Star ◽  
Magnetic Fields ◽  
Magnetic Dipole ◽  
Maxwell Equations ◽  
Magnetic Dipole Moment ◽  
Polar Angle ◽  
Gravitational Redshift ◽  
Schwarzschild Solution ◽  
Emission Signal

We consider the analytical Bonnor solution for a relativistic neutron star and discuss about the limit in which this solution satisfies Einstein-Maxwell equations. We study the gravitational redshift for Bonnor solution without electric charge. We find that for stars with magnetic fields up to [Formula: see text] in the center, the gravitational redshift for Bonnor metric differs from the Schwarzschild solution on a term that depends on magnetic dipole moment and the polar angle of the emission signal.

scholarly journals The properties of the massive neutron star PSR J0348+0432

2015 ◽  
Vol 24 (08) ◽  
pp. 1550058 ◽  
Author(s):  
Xian-Feng Zhao
Keyword(s):  
Neutron Star ◽  
Energy Density ◽  
Mean Field ◽  
Coupling Constants ◽  
Gravitational Redshift ◽  
Central Pressure ◽  
Relativistic Mean Field ◽  
Massive Neutron Star ◽  
Central Energy ◽  
Well Depth

The properties of the massive neutron star PSR J0348+0432 is calculated in the framework of the relativistic mean field (RMF) theory by choosing the suitable hyperon coupling constants. It is found that the central energy density ϵc and the central pressure pc of the massive neutron star PSR J0348+0432 respectively are 1.5 times larger and 3.6 times larger than those of the canonical mass neutron star. It is also found that in the neutron star PSR J0348+0432 there are five kinds of baryons appearing: n, p, Λ, Ξ- and Ξ0 but in the canonical mass neutron star there are only three kinds of particles appearing: n, p and Λ. In our models, the positive well depth [Formula: see text] will restrict the production of the hyperons Σ-, Σ0 and Σ+ and therefore either in the neutron star PSR J0348+0432 or in the canonical mass neutron star the hyperons Σ-, Σ0 and Σ+ all do not appear. In addition, our results also show that the radius R of the massive neutron star PSR J0348+0432 is less than that of the canonical mass neutron star while the gravitational redshift of the former is larger than that of the latter.

A well-behaved charged anisotropic Tolman VII space–time

2016 ◽  
Vol 94 (10) ◽  
pp. 1017-1023 ◽  
Author(s):  
Ksh. Newton Singh ◽  
Farook Rahaman ◽  
Neeraj Pant
Keyword(s):  
Exact Solution ◽  
Neutron Star ◽  
Sound Speed ◽  
Space Time ◽  
Compact Stars ◽  
Gravitational Redshift ◽  
Quark Star ◽  
Type Solution ◽  
Anisotropic Solution ◽  
Transverse Pressure

We present a new exact solution of charged anisotropic Tolman VII type solution representing compact stars. Here the transverse pressure and sound speed are decreasing in nature and well behaved. These solutions can be used to model both neutron star and quark star within the range of observed masses and radii. For particular values of constant parameters, we present a neutron star of mass 0.924 [Formula: see text] with radius 11.55 km and a quark star of mass 0.7 [Formula: see text] with radius 8.76 km. The model predicts a surface gravitational redshift of 0.145 for a particular choice of constant parameters. Also, the compactness parameter (i.e., M/R = 0.119) is less than 4/9 and satisfies the Buchdahl–Andréasson limit. Indeed, our charged anisotropic solution also satisfies the Cooperstock and De La Cruz condition as M/Q = 13.74 > 1, which is needed for a configuration to be at equilibrium.

scholarly journals A Hypothesis about the Predominantly Gravitational Nature of Redshift in the Electromagnetic Spectra of Space Objects

2020 ◽  
Author(s):  
Stepan Tiguntsev
Keyword(s):  
Neutron Star ◽  
Computational Experiments ◽  
Gravitational Redshift ◽  
Electromagnetic Spectrum ◽  
The Sun ◽  
Stationary Source ◽  
The Earth ◽  
Space Objects ◽  
The Relationship

Abstract The study theoretically substantiates the relationship between the redshift in the electromagnetic spectrum of space objects and their gravity and demonstrates it with computational experiments. Redshift, in this case, is a consequence of a decrease in the speed of the photons emitted from the surface of objects, which is caused by the gravity of these objects. The decline in the speed of photons due to the gravity of space gravitating object (GO) is defined as ΔC = C-C ', where: C' is the photon speed changed by the time the receiver records it. Then, at a change in the photon speed between a stationary source and a receiver, the redshift factor is determined as Z = (C-C ')/C'. Computational experiments determined the gravitational redshift of the Earth, the Sun, a neutron star, and a quasar. Graph of the relationship between the redshift and the ratio of sizes to the mass of any space GOs was obtained. The findings indicate that the distance to space objects does not depend on the redshift of these objects.

scholarly journals A Hypothesis about the Predominantly Gravitational Nature of Redshift in the Electromagnetic Spectra of Space Objects

2020 ◽  
Author(s):  
Stepan Tiguntsev
Keyword(s):  
Neutron Star ◽  
Computational Experiments ◽  
Gravitational Redshift ◽  
Electromagnetic Spectrum ◽  
The Sun ◽  
Stationary Source ◽  
The Earth ◽  
Space Objects ◽  
The Relationship

Abstract The study theoretically substantiates the relationship between the redshift in the electromagnetic spectrum of space objects and their gravity and demonstrates it with computational experiments. Redshift, in this case, is a consequence of a decrease in the speed of the photons emitted from the surface of objects, which is caused by the gravity of these objects. The decline in the speed of photons due to the gravity of space gravitating object (GO) is defined as ΔC = C-C ', where: C' is the photon speed changed by the time the receiver records it. Then, at a change in the photon speed between a stationary source and a receiver, the redshift factor is determined as Z = (C-C ')/C'. Computational experiments determined the gravitational redshift of the Earth, the Sun, a neutron star, and a quasar. Graph of the relationship between the redshift and the ratio of sizes to the mass of any space GOs was obtained. The findings indicate that the distance to space objects does not depend on the redshift of these objects.

Sign in / Sign up

Export Citation Format

Share Document