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Pulsar magnetospheres are shaped by ultra-relativistic electron/positron plasmas flowing in a strong magnetic field and subject to strong gravitational fields. The former induces magnetospheric currents and space charges responsible for the…

High Energy Astrophysical Phenomena · Physics 2015-12-09 J. Petri

The Einstein equations for a plane-symmetric gravitational field coupled to an arbitrary nonlinear sigma model (NSM) are shown to be represented in the form of dynamical equations of a {\it generalized effective NSM}. The gravitational…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. V. Chervon , D. Yu. Shabalkin

We derive the generalized Gauss-Codazzi-Mainardi (GCM) equation for a general affine connection with torsion and non-metricity. Moreover, we show that the metric compatibility and torsionless condition of a connection on a manifold are…

General Relativity and Quantum Cosmology · Physics 2021-08-02 Seramika Ariwahjoedi , Agus Suroso , F. P. Zen

We analyze the cosmology of a general Scalar-Tensor theory which encompasses generalized Brans-Dicke theory, Gauss-Bonnet gravity, non-minimal derivative gravity, generalized Galileon gravity and also the general k-essence type models.…

General Relativity and Quantum Cosmology · Physics 2017-03-07 Erfan Masaeli , Meysam Motaharfar , Hamid Reza Sepangi

(Abridged) We develop an analytical spectral method to solve the equations of equilibrium for a self-gravitating, magnetized fluid body, under the only hypotheses that (a) the equation of state is isothermal, (b) the configuration is…

Astrophysics · Physics 2009-11-10 Daniele Galli

Historically, the discovery of symmetries has played an important role in the progress of our fundamental understanding of nature. This paper will demonstrate that there exists in Newtonian theory in a spherical gravitational field a formal…

General Physics · Physics 2014-07-18 Armin Nikkhah Shirazi

As a low energy effective field theory, classical General Relativity receives an infrared relevant modification from the conformal trace anomaly of the energy-momentum tensor of massless, or nearly massless, quantum fields. The local form…

General Relativity and Quantum Cosmology · Physics 2018-10-04 Emil Mottola

The solutions of $U(1)$ gauge-gravity coupling is one of the interesting models for analyzing the semi-classical nature of spacetime. In this regard, different well-known singular and nonsingular solutions have been taken into account. The…

General Relativity and Quantum Cosmology · Physics 2018-06-06 Seyed Hossein Hendi , Behzad Eslam Panah , Shahram Panahiyan , Mehrab Momennia

Following the basic principles of a charge separated pulsar magnetosphere \citep{goldreich1969}, we consider the magnetosphere be stationary in space, instead of corotating, and the electric field be uploaded from the potential distribution…

High Energy Astrophysical Phenomena · Physics 2015-07-01 K. H. Tsui

Utilizing various gauges of the radial coordinate we give a description of static spherically symmetric space-times with point singularity at the center and vacuum outside the singularity. We show that in general relativity (GR) there exist…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Plamen Fiziev

The concept of magnetic connections is extended to non-ideal relativistic magnetohydrodynamical plasmas. Adopting a general set of equations for relativistic magnetohydrodynamics including thermal-inertial, thermal electromotive, Hall and…

Plasma Physics · Physics 2015-05-05 Felipe A. Asenjo , Luca Comisso

Magnetars have inferred polar field strengths in excess of the Schwinger limit, where non-linear electromagnetic effects can be significant. Their internal fields may be even stronger, suggesting that Maxwellian characterizations of…

High Energy Astrophysical Phenomena · Physics 2025-05-12 Arthur G. Suvorov , José A. Pons

In this article, we focus on symmetric teleparallel gravity, a modification of General Relativity where gravity is described by the non-metricity of an affine connection, whose curvature and torsion vanish. In these theories, the…

General Relativity and Quantum Cosmology · Physics 2024-12-17 Manuel Hohmann , Vasiliki Karanasou

The close vicinity of neutron stars remains poorly constrained by observations. Although plenty of data are available for the peculiar class of pulsars we are still unable to deduce the underlying plasma distribution in their magnetosphere.…

High Energy Astrophysical Phenomena · Physics 2015-06-23 J. Pétri

The general-relativistic (GR) magnetohydrodynamic (MHD) equations for a conductive plasma fluid are derived and discussed in the curved spacetime described by Thorne's metric tensor, i.e., a family of cosmological models with inherent…

General Relativity and Quantum Cosmology · Physics 2023-06-16 Kostas Kleidis , Apostolos Kuiroukidis , Demetrios B. Papadopoulos

The field theoretical description of the general relativity (GR) is further developed. The action for the gravitational field and its sources is given explicitely. The equations of motion and the energy-momentum tensor for the gravitational…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. V. Babak , L. P. Grishchuk

A modification of General Relativity that is based on the gravitational Standard-Model Extension and incorporates nondynamical background fields has recently been studied via the ADM formalism. Our objective in this paper is to develop a…

General Relativity and Quantum Cosmology · Physics 2023-05-15 Carlos M. Reyes , Marco Schreck

The intense magnetic fields inferred from magnetars suggest they may be strong gravitational-wave emitters. Although emissions due to hydromagnetic deformations are more promising from a detection standpoint, exterior fields also contribute…

General Relativity and Quantum Cosmology · Physics 2025-10-09 Arthur G. Suvorov , Petros Stefanou , José A. Pons

We first investigate the form the General Relativity Theory would have taken had the gravitational mass and the inertial mass of material objects been different. We then extend this analysis to electromagnetism and postulate an equivalence…

General Relativity and Quantum Cosmology · Physics 2020-01-09 Murat Özer

We present a detailed analysis of the properties of twisted, force-free magnetospheres of non-rotating neutron stars, which are of interest in the modelling of magnetar properties and evolution. In our models the magnetic field smoothly…

High Energy Astrophysical Phenomena · Physics 2018-10-11 Taner Akgün , Juan Antonio Miralles , José A. Pons , Pablo Cerdá-Durán