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In the framework of Einstein-Maxwell-axion theory we consider static spherically symmetric solutions, which describe a magnetic monopole in the axionic environment. These solutions are interpreted as the solutions for an axionic dyon, the…

General Relativity and Quantum Cosmology · Physics 2017-08-08 Alexander B. Balakin , Alexei E. Zayats

We present cosmological solutions for (1+3+n)-dimensional steady state universe in dilaton gravity with an arbitrary dilaton coupling constant w and exponential dilaton self-interaction potentials in the string frame. We focus particularly…

General Relativity and Quantum Cosmology · Physics 2013-03-01 Ozgur Akarsu , Tekin Dereli

The fundamental metrics, which describe any static three-dimensional Einstein-Maxwell spacetime (depending only on a unique spacelike coordinate), are found. In this case there are only three independent components of the electromagnetic…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Mauricio Cataldo

We prove area inequalities for stable marginally outer trapped surfaces in Einstein-Maxwell-dilaton theory. Our inspiration comes on the one hand from a corresponding upper bound for the area in terms of the charges obtained recently by…

General Relativity and Quantum Cosmology · Physics 2015-09-01 David Fajman , Walter Simon

We present a simplified model in which we suggest that two important galactic problems -the magnetic field configuration at large scales and the flat rotation curve- may be simultaneously explained. A highly convective disc produces a high…

Astrophysics · Physics 2007-05-23 E. Battaner , H. Lesch , E. Florido

In a recent paper [Phys. Rev. D{\bf 85}, 023528 (2012)] the authors proposed a generalized Born-Infeld electrodynamics coupled to general relativity which produces a nonsingular bouncing universe. For a magnetic universe the resulting…

General Relativity and Quantum Cosmology · Physics 2014-12-10 Ricardo Garcia-Salcedo , Tame Gonzalez , Israel Quiros

We apply a Harrison transformation to higher dimensional asymptotically flat black hole solutions, which puts them into an external magnetic field. First, we magnetize the Schwarzschild-Tangherlini metric in arbitrary spacetime dimension…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Marcello Ortaggio

New solutions are derived in the $2+1$ gravity which is coupled to $|{\cal F}|^k$ type non-linear electric field in Maxwell Power theory with dilaton field. We obtain consistent solutions in general $k$ case. We also investigate the…

General Relativity and Quantum Cosmology · Physics 2015-01-28 Masashi Kuniyasu

A direct construction of equilibrium magnetic fields with toroidal topology at arbitrary order in the distance from the magnetic axis is carried out, yielding an analytical framework able to explore the landscape of possible magnetic flux…

Plasma Physics · Physics 2020-01-29 R. Jorge , W. Sengupta , M. Landreman

Aims. Many recent observations of pulsars and magnetars can be interpreted in terms of neutron stars (NS) with multipole electromagnetic fields. As a first approximation, we investigate the multipole magnetic and electric fields in the…

High Energy Astrophysical Phenomena · Physics 2020-07-07 S. Bonazzola , F. Mottez , J. Heyvaerts

Observationally, magnetic fields reach equipartition with thermal energy and cosmic rays in the interstellar medium of disk galaxies such as the Milky Way. However, thus far cosmological simulations of the formation and evolution of…

Astrophysics of Galaxies · Physics 2015-06-18 R. Pakmor , F. Marinacci , V. Springel

We have extended our previous mean-field galactic dynamo model which included algebraic and dynamic alpha nonlinearities (Kleeorin et al., A&A, v. 387, 453, 2002), to include also a quenching of turbulent diffusivity. We readily obtain…

Astrophysics · Physics 2014-10-13 N. Kleeorin , D. Moss , I. Rogachevskii , D. Sokoloff

We consider electromagnetic field quantization in an expanding universe. We find that the covariant (Gupta-Bleuler) method exhibits certain difficulties when trying to impose the quantum Lorenz condition on cosmological scales. We thus…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-21 Jose Beltran Jimenez , Antonio L. Maroto

We present a space-velocity theory of gravitation in a 4-dimensional curved space. The solutions of the field equations yield 3 possibilities for the universe expansion but only the accelerating one is possible. Although the theory has no…

Astrophysics · Physics 2007-05-23 Moshe Carmeli

We identify a string theory counterpart of the dilatonic Melvin D=4 background describing a "magnetic flux tube" in low-energy field theory limit. The corresponding D=5 bosonic string model containing extra compact Kaluza-Klein dimension is…

High Energy Physics - Theory · Physics 2009-09-17 A. A. Tseytlin

Within the context of general relativity we study in a fully covariant way the so-called Euler-Maxwell system of equations. In particular, on decomposing the aforementioned system into its 1 temporal and 1 + 2 spatial components at the…

General Relativity and Quantum Cosmology · Physics 2022-04-04 Panagiotis Mavrogiannis , Christos G. Tsagas

Analytical models of axially symmetric thin disks of finite extension in presence of magnetic field are presented based on the well-known Morgan-Morgan solutions. The source of the magnetic field is cons\-tructed separating the equation…

Astrophysics of Galaxies · Physics 2016-04-11 Edinson Cardona-Rueda , Gonzalo García-Reyes

The existence of global weak solutions to a coupled spin drift-diffusion and Maxwell-Landau-Lifshitz system is proved. The equations are considered in a two-dimensional magnetic layer structure and are supplemented with Dirichlet-Neumann…

Analysis of PDEs · Mathematics 2015-08-12 Nicola Zamponi , Ansgar Jüngel

Spherically symmetric solutions with a flux of electric and magnetic fields in Kaluza-Klein gravity are considered. It is shown that under the condition (electric charge $q$) $\approx$ (magnetic charge $Q$) ($q>Q$) these solutions are like…

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

We analytically find the exact propagation modes of the electromagnetic and the Kalb-Ramond fields together in a five-dimensional curved space-time. The existence and localization of gauge particles into our four-dimensional world (4D) is…

High Energy Physics - Theory · Physics 2010-10-27 H. R. Christiansen , M. S. Cunha , M. O. Tahim