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Related papers: Self-gravity at the scale of the polar cell

200 papers

An error in the gravitational force that the source of gravity induces on itself (a self-force error) violates both the conservation of linear momentum and the conservation of energy. If such errors are present in a self-gravitating system…

Instrumentation and Methods for Astrophysics · Physics 2021-05-03 Hanjue Zhu , Nickolay Y. Gnedin

We derive easy-to-handle approximations for the polar gap electric field due to inertial frame dragging as derived by Harding & Muslimov 1998. A simple formula valid for polar gap height comparable to the polar cap radius is presented.

Astrophysics · Physics 2007-05-23 J. Dyks , B. Rudak

We obtain an upper bound on the lowest magnetic Neumann eigenvalue of a bounded, convex, smooth, planar domain with moderate intensity of the homogeneous magnetic field. This bound is given as a product of a purely geometric factor…

Spectral Theory · Mathematics 2023-12-12 Ayman Kachmar , Vladimir Lotoreichik

A model for the static weak-field macroscopic medium is analyzed and the equation for the macroscopic gravitational potential is derived. This is a biharmonic equation which is a non-trivial generalization of the Poisson equation of…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Giovanni Montani , Remo Ruffini , Roustam Zalaletdinov

We introduce a unified approach that, given a strong gravitationally lensed polarised source, self-consistently infers its complex surface brightness distribution and the lens galaxy mass-density profile, magnetic field and electron density…

Astrophysics of Galaxies · Physics 2024-07-30 S. Ndiritu , S. Vegetti , D. M. Powell , J. P. McKean

In this paper, we analyze electric deflection fields for polar molecules in terms of a multipole expansion and derive a simple but rather insightful expression for the force on the molecules. Ideally, a deflection field exerts a strong,…

Atomic Physics · Physics 2017-09-13 Adrian J. de Nijs , Hendrick L. Bethlem

We have developed a computational package for the calculation of numerically exact internal and external gravitational potential, its functional derivatives and sensitivity kernels, in an aspherical, heterogeneous planet. We detail our…

Geophysics · Physics 2025-08-12 Alex D. C. Myhill , Matthew A. Maitra , David Al-Attar

Using the Post-Minkowskian formalism and considering rotation as a perturbation, we compute an approximate interior solution for a stationary perfect fluid with constant density and axial symmetry. A suitable change of coordinates allows…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. A. Cabezas , E. Ruiz

Mimetic gravity is analysed in the framework of some extensions of General Relativity, where a function of the Gauss-Bonnet invariant in four dimensions is considered. By assuming the so-called mimetic condition, the conformal degree of…

General Relativity and Quantum Cosmology · Physics 2018-05-22 Yi Zhong , Diego Saez-Chillon Gomez

We deploy and demonstrate the capabilities of the magnetic field model developed by Ewertowski & Basu (2013) by fitting observed polarimetry data of the prestellar core FeSt 1-457. The analytic hourglass magnetic field function derived…

Solar and Stellar Astrophysics · Physics 2021-04-21 Gianfranco Bino , Shantanu Basu

A new computationally efficient method has been introduced to treat self-gravity in mesh based hydrodynamical simulations. It is applied simply by slightly modifying the Poisson equation into an inhomogeneous wave equation. This roughly…

Instrumentation and Methods for Astrophysics · Physics 2016-04-20 Ryosuke Hirai , Hiroki Nagakura , Hirotada Okawa , Kotaro Fujisawa

We assume that the points in volumes smaller than an elementary volume (which may have a Planck size) are indistinguishable in any physical experiment. This naturally leads to a picture of a discrete space with a finite number of degrees of…

High Energy Physics - Theory · Physics 2026-01-07 Ali H. Chamseddine , Viatcheslav Mukhanov

In this paper, we obtain analytical approximate black hole solutions in the framework of $f(R)$ gravity and the absence of a cosmological constant. In this area, we apply the equations of motion of the theory to a spherically symmetric…

General Relativity and Quantum Cosmology · Physics 2023-03-08 Seyed Naseh Sajadi , Ali Hajilou , Seyed Hossein Hendi

We have developed in the past several algorithms with intrinsic complexity bounds for the problem of point finding in real algebraic varieties. Our aim here is to give a comprehensive presentation of the geometrical tools which are…

Algebraic Geometry · Mathematics 2009-11-23 B. Bank , M. Giusti , J. Heintz , M. Safey El Din , E. Schost

Spatially homogeneous thermal equilibria of self-gravitating gas, being impossible otherwise, are nevertheless allowed in an expanding background accounting for Universe's expansion. Furthermore, a fixed density at the boundary of a…

Astrophysics of Galaxies · Physics 2024-12-13 Zacharias Roupas

We construct hypergravity theory in three-dimensions with the gravitino \psi_{\mu m_1... m_n}{}^A with an arbitrary half-integral spin n+3/2, carrying also the index A for certain real representations of any gauge group G. The possible real…

High Energy Physics - Theory · Physics 2009-11-11 Hitoshi Nishino , Subhash Rajpoot

A metric-field approach to gravitation is presented. It is based on an idea of dependency of space-time properties on measuring instruments. Some bimetric equations that realize this idea are considered. They were tested by the binary…

General Relativity and Quantum Cosmology · Physics 2009-11-07 L. V. Verozub

We investigate the internal structure of the current sheet in the pulsar wind within force-free and two-fluid MHD approximations. Within the force-free approximation we obtain general asymptotic solution of the Grad-Shafranov equation for…

High Energy Astrophysical Phenomena · Physics 2018-01-24 V. V. Prokofev , L. I. Arzamasskiy , V. S. Beskin

From a sample of 15651 RR Lyrae with accurate proper motions in Gaia DR2, we measure the azimuthally averaged kinematics of the inner stellar halo between 1.5 kpc and 20 kpc from the Galactic centre. We find that their kinematics are…

Astrophysics of Galaxies · Physics 2019-03-06 Christopher Wegg , Ortwin Gerhard , Marie Bieth

It is known that a near-extremal Kerr black hole can be spun up beyond its extremal limit by capturing a test particle. Here we show that overspinning is always averted once back-reaction from the particle's own gravity is properly taken…

General Relativity and Quantum Cosmology · Physics 2015-08-18 Marta Colleoni , Leor Barack , Abhay G. Shah , Maarten van de Meent