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Related papers: Pulse profiles from a pulsar in scalar-tensor grav…

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A simple model of a spherically symmetric, pulsating star is calculated. The application to the Sun gives a 166-min radial pulsation. The theory of gravitation in flat space-time implies for a spherically symmetric, nonstationary star small…

General Physics · Physics 2010-02-09 Walter Petry

The universal relationships for compact stars have been investigated employing perturbative approach using canonical (APR) and Brussels-Montreal Skyrme (BSk22, BSk24, BSk26) equations of state describing hadronic matter of neutron stars.…

Nuclear Theory · Physics 2024-08-02 Debasis Atta , Vinay Singh , D. N. Basu

Both neutron stars and strange stars are capable of supporting fast rotations observed in pulsars. On the basis of this it has been argued that some of the pulsars could be strange stars. We investigate whether strange stars can sustain…

Astrophysics · Physics 2007-05-23 Sushan Konar

The sizes of pulsar radio pulses in the plane of the sky are determined. This is important not only in relation to the possibility of directly resolving the radio pulses spatially, but also for verifying and placing constraints on existing…

High Energy Astrophysical Phenomena · Physics 2015-06-23 H. L. Hakobyan , V. S. Beskin

A forefront area of research concerns the exploration of the properties of hadronic matter under extreme conditions of temperature and density, and the determination of the equation of state--the relation between pressure, temperature and…

Astrophysics · Physics 2008-11-26 F. Weber , R. Negreiros , P. Rosenfield , M. Stejner

Proto-neutron stars are born when a highly evolved and massive star collapses under gravity. In this paper, we investigate the spontaneous scalarization in proto-neutron stars. Based on the scalar tensor theory of gravity as well as the…

High Energy Astrophysical Phenomena · Physics 2025-10-08 Fahimeh Rahimi , Zeinab Rezaei

In nonminimally coupled theories where a scalar field is coupled to the Ricci scalar, neutron stars (NSs) can have scalar charges through an interaction with matter mediated by gravity. On the other hand, the same theories do not give rise…

General Relativity and Quantum Cosmology · Physics 2025-03-03 Hiroki Takeda , Shinji Tsujikawa , Atsushi Nishizawa

The nature of pulsar is still unknown because of non-perturbative effects of the fundamental strong interaction, and different models of pulsar inner structures are then suggested, either conventional neutron stars or quark stars.…

High Energy Astrophysical Phenomena · Physics 2013-04-30 Jiguang Lu , Renxin Xu , Hua Feng

Pulsar timing arrays provide a unique means to detect nanohertz gravitational waves through long-term measurements of pulse arrival times from an ensemble of millisecond pulsars. After years of observations, some timing array pulsars have…

High Energy Astrophysical Phenomena · Physics 2020-07-30 Boris Goncharov , Xing-Jiang Zhu , Eric Thrane

We describe the X-ray pulse profile models we use, and how we use them, to analyze Neutron Star Interior Composition Explorer (NICER) observations of rotation-powered millisecond pulsars to obtain information about the mass-radius relation…

Models of relativistic rotating neutron star composed of hyperon rich matter is constructed in the framework of an effective field theory in the mean-field approach. The gross properties of compact star is calculated at both static and the…

Nuclear Theory · Physics 2009-05-12 B. K. Sharma , T. K. Jha

The general properties of the non-thermal non-pulsed X-ray emission of rotation powered pulsars are investigated in the context of a pulsar wind nebula model. An examination of the observed X-ray emission from a sample of 23 pulsars from…

Astrophysics · Physics 2016-08-30 K. S. Cheng , Ronald E. Taam , W. Wang

The spectrum of frequencies and characteristic times that compose the ringdown phase of gravitational waves emitted by neutron stars carries information about the matter content (the equation of state) and the underlying theory of gravity.…

General Relativity and Quantum Cosmology · Physics 2020-07-01 Jose Luis Blázquez-Salcedo , Fech Scen Khoo , Jutta Kunz

New-generation X-ray polarimeters currently under development promise to open a new window in the study of high-energy astrophysical sources. Among them, neutron stars appear particularly suited for polarization measurements. Radiation from…

High Energy Astrophysical Phenomena · Physics 2015-09-24 Roberto Taverna , Roberto Turolla , Denis Gonzalez Caniulef , Silvia Zane , Fabio Muleri , Paolo Soffitta

In the last few years considerable observational resources have been devoted to study the thermal emission from isolated neutron stars. Detailed XMM and Chandra observations revealed a number of features in the X-ray pulse profile, like…

Astrophysics · Physics 2009-11-10 Silvia Zane , Roberto Turolla

Disk-fed accretion onto neutron stars can power a wide range of astrophysical sources ranging from X-ray binaries, to accretion powered millisecond pulsars, ultra-luminous X-ray sources, and gamma-ray bursts. A crucial parameter controlling…

High Energy Astrophysical Phenomena · Physics 2023-11-17 Ariadna Murguia-Berthier , Kyle Parfrey , Alexander Tchekhovskoy , Jonatan Jacquemin-Ide

We study neutron star configurations in a simple shift-symmetric subfamily of degenerate higher-order scalar-tensor (DHOST) theories, whose deviations from General Relativity (GR) are characterized by a single parameter. We compute the…

General Relativity and Quantum Cosmology · Physics 2022-11-09 Hamza Boumaza , David Langlois

Recently in boson star models in framework of Brans-Dicke theory, three possible definitions of mass have been identified, all identical in general relativity, but different in scalar-tensor theories of gravity.It has been conjectured that…

General Relativity and Quantum Cosmology · Physics 2010-04-06 S. Yazadjiev

We investigate the dependence of pulse amplitudes of accreting millisecond pulsars on the masses of the neutron stars. Because the pulsation amplitudes are suppressed as the neutron stars become more massive, the probability of detection of…

Astrophysics · Physics 2011-02-11 Feryal Ozel

In the present paper we construct novel non-topological, spontaneously scalarized neutron stars in multi-scalar Gauss-Bonnet gravity with maximally symmetric target space, and nontrivial map $\varphi:spacetime \rightarrow target\ space$.…

General Relativity and Quantum Cosmology · Physics 2022-02-23 Kalin V. Staykov , Radostina Z. Zheleva