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

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Pulse profile modelling is a relativistic ray-tracing technique that can be used to infer masses, radii and geometric parameters of neutron stars. In a previous study, we looked at the performance of this technique when applied to…

Pulsars are rotating neutron stars which emit lighthouse-like beams. Owing to their unique properties, pulsars are a unique astrophysical tool to test general relativity, inform on matter at extreme densities, and probe galactic magnetic…

Instrumentation and Methods for Astrophysics · Physics 2019-07-24 Renaud Gueroult , Yuan Shi , Jean-Marcel Rax , Nathaniel J. Fisch

Using a metric perturbation method, we study gravitational waves from a test particle scattered by a spherically symmetric relativistic star. We calculate the energy spectrum and the waveform of gravitational waves for axial modes. Since…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Kazuhiro Tominaga , Motoyuki Saijo , Kei-ichi Maeda

Isolated neutron stars (NSs) show a bewildering variety of astrophysical manifestations, presumably shaped by the magnetic field strength and topology at birth. Here, using state-of-the art calculations of the coupled magnetic and thermal…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Rosalba Perna , Daniele Vigano' , Jose' A. Pons , Nanda Rea

Rotation-powered "recycled" millisecond pulsars are a variety of rapidly-spinning neutron stars that typically show thermal X-ray radiation due to the heated surface of their magnetic polar caps. Detailed numerical modeling of the…

High Energy Astrophysical Phenomena · Physics 2016-03-23 Slavko Bogdanov

We computed flat rotation curves from scalar-tensor theories in their weak field limit. Our model, by construction, fits a flat rotation profile for velocities of stars. As a result, the form of the scalar field potential and DM…

Astrophysics · Physics 2008-11-26 Jorge L. Cervantes-Cota , M. A. Rodriguez-Meza , Dario Nunez

There are now about fifty known radio pulsars in binary systems, including at least five in double neutron star binaries. In some cases, the stellar masses can be directly determined from measurements of relativistic orbital effects. In…

Astrophysics · Physics 2009-10-30 S. E. Thorsett , Deepto Chakrabarty

The radiation of a pulsar wind is computed assuming that at roughly 10 to 100 light cylinder radii from the star, magnetic energy is dissipated into particle energy. The synchrotron emission of heated particles appears periodic, with, in…

Astrophysics · Physics 2009-11-07 J. G. Kirk , O. Skjaeraasen , Y. A. Gallant

This talk reviews the constraints imposed by binary-pulsar data on gravity theories, focusing on ``tensor-scalar'' ones which are the best motivated alternatives to general relativity. We recall that binary-pulsar tests are qualitatively…

General Relativity and Quantum Cosmology · Physics 2016-11-09 Gilles Esposito-Farese

We investigate the chances that neutron stars act as the lense in a gravitational microlensing event towards the galactic bulge or a spiral arm. The observation of neutron stars by means of gravitational microlensing would allow the…

Astrophysics · Physics 2009-11-07 Dominik J. Schwarz , Dirk Seidel

Scalar-tensor theories of gravity modify General Relativity by introducing a scalar field that couples non-minimally to the metric tensor, while satisfying the weak-equivalence principle. These theories are interesting because they have the…

General Relativity and Quantum Cosmology · Physics 2017-09-27 David Anderson , Nicolas Yunes

We introduce a model for pulsars in which non-radial oscillations of high spherical degree (l) aligned to the magnetic axis of a spinning neutron star reproduce the morphological features of pulsar beams. In our model, rotation of the…

Astrophysics · Physics 2009-11-10 J. Christopher Clemens , R. Rosen

We investigate the nonrotating neutron stars in $f(T)$ gravity with $f(T)=T+\alpha{T}^2$, where $T$ is the torsion scalar in the teleparallel formalism of gravity. In particular, we utilize the SLy and BSk family of equations of state for…

General Relativity and Quantum Cosmology · Physics 2022-04-27 Rui-Hui Lin , Xiao-Ning Chen , Xiang-Hua Zhai

We present an analytical study of light curves of slowly rotating radio pulsars with emphasis on the chromatic effects derived from the presence of a plasma environment; analyzing the effects of the compactness, the metric model, and the…

High Energy Astrophysical Phenomena · Physics 2023-02-27 Gastón Briozzo , Emanuel Gallo

A remarkably precise observational relation for pulse core component widths of radio pulsars is used to derive stringent limits on pulsar radii, strongly indicating that pulsars are strange stars rather than neutron stars. This is achieved…

Astrophysics · Physics 2009-10-31 R. C. Kapoor , C. S. Shukre

We study the microlensing of Non-Radially Pulsating (NRP) stars. Pulsations are formulated for stellar radius and temperature using spherical harmonic functions with different values of l,m. The characteristics of the microlensing light…

Solar and Stellar Astrophysics · Physics 2020-09-09 Sedighe Sajadian , Richard Ignace

The gravitational field of a laser pulse of finite lifetime, is investigated in the framework of linearized gravity. Although the effects are very small, they may be of fundamental physical interest. It is shown that the gravitational field…

Quantum Physics · Physics 2017-01-04 Dennis Rätzel , Martin Wilkens , Ralf Menzel

We present new results for pulsating stars in general relativity. First we show that the so-called gravitational-wave modes of a neutron star can be excited when a gravitational wave impinges on the star. Numerical simulations suggest that…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Nils Andersson , Kostas D. Kokkotas

The glitch activity of young pulsars arises from the exchange of angular momentum between the crust and the interior of the star. Recently, it was inferred that the moment of inertia of the crust of a neutron star is not sufficient to…

General Relativity and Quantum Cosmology · Physics 2016-08-02 Kalin Staykov , K. Yavuz Ekşi , Stoytcho S. Yazadjiev , M. Metehan Türkoğlu , A. Savaş Arapoğlu

Hybrid neutron stars, the compact objects consisting hadronic matter and strange quark matter, can be considered as the probes for the scalar tensor gravity. In this work, we explore the scalarization of hybrid neutron stars in the scalar…

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