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Related papers: Approximate Spacetime for Neutron Stars

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The Neutron Star Interior Composition Explorer (NICER) mission has provided a unique opportunity to constrain the equation of state of neutron stars by using the technique of pulse-profile modelling. This technique requires accurate and…

General Relativity and Quantum Cosmology · Physics 2021-05-12 G. André Oliva , Francisco Frutos-Alfaro

The realistic models of neutron stars are considered for simple $R+\alpha R^2$ gravity and equivalent Brance-Dicke theory with dilaton field in Einsein frame. For negative values of $\alpha$ we have no acceptable results from astrophysical…

General Relativity and Quantum Cosmology · Physics 2018-12-27 Artyom V. Astashenok , Alexey S. Baigashov , Sergey A. Lapin

Ghost neutrinos in radiative Kerr spacetime endowed with totally skew-symmetric Cartan contortion is presented. The computations are made by using the Newman-Penrose (NP) calculus. The model discussed here maybe useful in several…

General Relativity and Quantum Cosmology · Physics 2007-05-23 L. C. Garcia de Andrade

If neutrinos have a small but non-zero mass, time-of-flight effects for neutrino bursts from distant sources can yield information on the large-scale geometry of the universe, the effects being proportional to the integral over time of the…

Astrophysics · Physics 2009-10-31 Leo Stodolsky

The parity doublet model, containing the SU(2) multiplets including the baryons identified as the chiral partners of the nucleons is applied to neutron stars. The maximum mass for the star is calculated for different stages of the cooling…

Astrophysics · Physics 2008-01-17 V. Dexheimer , S. Schramm , H. Stoecker

The lowest neutron star masses currently measured are in the range $1.0-1.1~M_\odot$, but these measurement have either large uncertainties or refer to isolated neutron stars. The recent claim of a precisely measured mass $M/M_{\odot} =…

High Energy Astrophysical Phenomena · Physics 2016-05-04 Hector O. Silva , Hajime Sotani , Emanuele Berti

Future X-ray missions, such as NICER and LOFT, together with gravitational-wave observations from ground-based detectors, will provide new insights into neutron stars. Interpreting accurate observations in the future will require accurate…

General Relativity and Quantum Cosmology · Physics 2025-05-27 Carlos Conde-Ocazionez , Tuojin Yin , Jaquelyn Noronha-Hostler , Nicolás Yunes

The equation of state for neutron stars in a wide-density range at zero temperature is constructed. The chiral quark-meson coupling model within relativistic Hartree-Fock approximation is adopted for uniform nuclear matter. The coupling…

High Energy Astrophysical Phenomena · Physics 2013-10-15 Tsuyoshi Miyatsu , Sachiko Yamamuro , Ken'ichiro Nakazato

We consider the three-dimensional rotating motions of neutron stars blown by the "axion wind". Neutron star precession and spin can change from the magnetic moment coupling to the oscillating axion background field, in analogy to the…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-21 Yiming Liu , Jinneng Luo , Sichun Sun

We study the properties of neutron stars adopting relativistic equations of state of neutron star matter, calculated in the framework of the relativistic Brueckner-Hartree-Fock approximation for electrically charge neutral neutron star…

Nuclear Theory · Physics 2009-10-30 H. Huber , F. Weber , M. K. Weigel , Ch. Schaab

We utilise the phenomenologically parameterized piecewise polytropic equations of state to study various neutron star properties. We investigate the compliance of these equations of state with several astronomical observations. We also…

Nuclear Theory · Physics 2022-05-04 Jaikhomba Singha , S. Mullai Vaneshwar , Ankit Kumar

We present a class of exact solutions of Einstein's gravitational field equations describing spherically symmetric and static anisotropic stellar type configurations. The solutions are obtained by assuming a particular form of the…

General Relativity and Quantum Cosmology · Physics 2017-10-04 T. Harko , M. K. Mak

We study trajectories of test particles around a luminous, static, spherically symmetric neutron star, under the combined influence of gravity and radiation. In general relativity, for Schwarzschild spacetime, an equilibrium sphere (the…

General Relativity and Quantum Cosmology · Physics 2024-09-06 Ronaldo S. S. Vieira , Maciek Wielgus

One of the primary science goals of the next generation of hard X-ray timing instruments is to determine the equation of state of the matter at supranuclear densities inside neutron stars, by measuring the radius of neutron stars with…

Regarding a $d-$dimensional spherically symmetric line element in the context of Einstein-$\Lambda$ gravity, the hydrostatic equilibrium equation of stars is obtained. Then, by using the lowest order constrained variational (LOCV) method…

General Relativity and Quantum Cosmology · Physics 2017-01-30 G. H. Bordbar , S. H. Hendi , B. Eslam Panah

We develop a new method to measure neutron star parameters and derive constraints on the equation of state of dense matter by fitting the frequencies of simultaneous Quasi Periodic Oscillation modes observed in the X-ray flux of accreting…

High Energy Astrophysical Phenomena · Physics 2020-09-02 Andrea Maselli , George Pappas , Paolo Pani , Leonardo Gualtieri , Sara Motta , Valeria Ferrari , Luigi Stella

We present a new numerical algorithm for the calculation of pulse profiles from spinning neutron stars in the Hartle-Thorne approximation. Our approach allows us to formally take into account the effects of Doppler shifts and aberration, of…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Dimitrios Psaltis , Feryal Ozel

Neutron stars are highly compact astrophysical objects and therefore of utmost relevance to learn about theories of gravity. Whereas the proper equation of state of the nuclear matter inside neutron stars is not yet known, and a wide range…

General Relativity and Quantum Cosmology · Physics 2022-04-28 Jutta Kunz

Neutron stars provide a natural laboratory for studying the properties of dense nuclear matter under extreme conditions. In this proceeding, we review our current understanding of dense isospin symmetric and asymmetric matter and neutron…

Nuclear Theory · Physics 2025-04-01 Rajesh Kumar , Veronica Dexheimer , Johannes Jahan

Neutron star matter is investigated in a hadronic chiral model approach using the lowest flavor-SU(3) multiplets for baryons and mesons. The parameters are determined to yield consistent results for saturated nuclear matter as well as for…

Astrophysics · Physics 2008-11-26 V. Dexheimer , S. Schramm , H. Stoecker