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Related papers: A Holographic Bound on Cosmic Magnetic Fields

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We numerically construct asymptotically $AdS$ black brane solutions of $D=4$ Einstein theory coupled to a scalar and two $U(1)$ gauge fields. The solutions are holographically dual to $d=3$ CFTs in a constant external magnetic field along…

High Energy Physics - Theory · Physics 2016-11-23 Aristomenis Donos , Christiana Pantelidou

The generation of large-scale magnetic fields is studied in inflationary cosmology. We consider the violation of the conformal invariance of the Maxwell field by dilatonic as well as non-minimal gravitational couplings. We derive a general…

Astrophysics · Physics 2009-11-11 Kazuharu Bamba , Misao Sasaki

We propose a mechanism for the generation of a magnetic field in the early universe during the QCD crossover assuming that dark matter is made of axions. Thermoelectric fields arise at pressure gradients in the primordial plasma due to the…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-18 Francesco Miniati , Gianluca Gregori , Brian Reville , Subir Sarkar

Existing theoretical and observational constraints on the abundance of magnetic monopoles are limited. Here we demonstrate that an ensemble of monopoles forms a plasma whose properties are well determined and whose collective effects place…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-05 Mikhail V. Medvedev , Abraham Loeb

Magnetic fields in the upper atmospheres of solar-like stars are believed to provide an enormous amount of energy to power the hot coronae and drive large-scale eruptions that could impact the habitability of planetary systems around these…

We investigate distribution of magnetic fields around dense solid plasmas generated by intense p-polarized laser (~10^{16} W.cm^{-2}, 100 fs) irradiation of magnetic tapes, using high sensitivity magneto optical microscopy. We present…

Other Condensed Matter · Physics 2009-11-13 Jaivardhan Sinha , Shyam Mohan , S. S. Banerjee , Subhendu Kahaly , G. Ravindra Kumar

Cosmic voids are magnetized at the level of at least $10^{-17}$ G on Mpc scales, as implied by blazar observations. We show that an electrically conducting plasma is present in the voids, and that, because of the plasma, \emph{diffusion}…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-21 Oindrila Ghosh , Axel Brandenburg , Chiara Caprini , Andrii Neronov , Franco Vazza

The presence of primordial magnetic fields increases the minimum halo mass in which star formation is possible at high redshifts. Estimates of the dynamical mass of ultra-faint dwarf galaxies (UFDs) within their half-light radius constrain…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-05 Mohammadtaher Safarzadeh , Abraham Loeb

Kilogauss-strength magnetic fields are often observed in intergranular lanes at the photosphere in the quiet Sun. Such fields are stronger than the equipartition field $B_e$, corresponding to a magnetic energy density that matches the…

Astrophysics · Physics 2009-11-13 P. J. Bushby , S. M. Houghton , M. R. E. Proctor , N. O. Weiss

Gravitational wave production induces a strong constraint on the amplitude of a primordial magnetic field. It has been shown that the nucleosynthesis bound for a stochastic gravitational wave background implies that causally generated…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-13 Chiara Caprini , Ruth Durrer , Elisa Fenu

Primordial magnetic fields (PMFs), which were generated in the early Universe before recombination, affect the motion of plasma and then the cosmic microwave background and the matter power spectrum. We consider constraints on PMFs with a…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-03 Dai G. Yamazaki , Kiyotomo Ichiki , Keitaro Takahashi

Spiral galaxies host dynamically important magnetic fields which can affect gas flows in the disks and halos. Total magnetic fields in spiral galaxies are strongest (up to 30 \muG) in the spiral arms where they are mostly turbulent or…

Astrophysics · Physics 2009-06-23 Rainer Beck

In this paper, we relate the complexity for a holographic state to a simple gravitational object of which the growth rate at late times is equal to temperature times black hole entropy. We show that if this is correct, the thermodynamics of…

High Energy Physics - Theory · Physics 2019-07-31 Zhong-Ying Fan , Minyong Guo

We study the generation of strong magnetic fields in magnetars and in the early universe. For this purpose we calculate the antisymmetric contribution to the photon polarization tensor in a medium consisting of an electron-positron plasma…

High Energy Physics - Phenomenology · Physics 2016-08-10 Maxim Dvornikov

Magnetic fields have been observed in galaxies, clusters of galaxies and probably in superclusters. While mechanisms exist to generate these in the late universe, it is possible that magnetic fields have existed since very early times. This…

Astrophysics · Physics 2009-12-07 Iain A. Brown

The propagation of ultra-high energy cosmic rays in extragalactic magnetic fields can be diffusive, depending on the strength and properties of the fields. In some cases the propagation time of the particles can be comparable to the age of…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Rafael Alves Batista , Guenter Sigl

Primordial magnetic field generated in the inflationary era can act as a viable source for the present day intergalactic magnetic field of sufficient strength. We present a fundamental origin for such a primordial generation of the magnetic…

General Relativity and Quantum Cosmology · Physics 2022-01-20 Sumanta Chakraborty , Supratik Pal , Soumitra SenGupta

Damping of magnetic fields via ambipolar diffusion and decay of magnetohydrodynamical (MHD) turbulence in the post decoupling era heats the intergalactic medium (IGM). Delayed recombination of hydrogen atoms in the IGM yields an optical…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-26 Kerstin E. Kunze , Eiichiro Komatsu

We investigate the effect of strong magnetic fields on the adiabatic radial oscillations of hadronic stars. We describe magnetized hadronic matter within the framework of the relativistic nonlinear Walecka model and integrate the equations…

High Energy Astrophysical Phenomena · Physics 2016-08-01 C. Vásquez Flores , L. B. Castro , G. Lugones

In the holographic description of cosmic preheating proposed in an accompanied Letter [1], the energy transfer between the inflaton and matter field at strong coupling is suggested to be mimicked by superfluid and normal components of a…

High Energy Physics - Theory · Physics 2021-04-07 Yi-Fu Cai , Shu Lin , Junyu Liu , Jia-Rui Sun