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The origin of the substantial magnetic fields that are found in galaxies and on even larger scales, such as in clusters of galaxies, is yet unclear. If the second-order couplings between photons and electrons are considered, then…

Detailed physical processes of magnetic field generation from density fluctuations in the pre-recombination era are studied. Solving Maxwell equations and the generalized Ohm's law, the evolutions of the net charge density, the electric…

Astrophysics · Physics 2008-11-26 Keitaro Takahashi , Kiyotomo Ichiki , Naoshi Sugiyama

Generating axion dark matter through the kinetic misalignment mechanism implies the generation of large asymmetries for Standard Model fermions in the early universe. Even if these asymmetries are washed out at later times, they can trigger…

High Energy Physics - Phenomenology · Physics 2023-08-09 Raymond T. Co , Valerie Domcke , Keisuke Harigaya

The magnetic fields observed in the Milky~Way and nearby galaxies appear to be in equipartition with the turbulent, thermal, and cosmic ray energy densities, and hence are expected to be dynamically important. However, the origin of these…

We investigate the $B+L$ violation process by performing three-dimensional lattice simulations in an electroweak theory with first-order phase transition and the electroweak sphaleron decay. The simulation results indicate that the…

High Energy Physics - Phenomenology · Physics 2021-09-01 Yuefeng Di , Jialong Wang , Ligong Bian , Rong-Gen Cai , Jing Liu

In an external magnetic field, the energy of the electroweak sphaleron---representing the energy barrier to baryon and lepton number violation---decreases but remains nonzero until the upper Ambjorn-Olesen critical field strength set by the…

High Energy Physics - Theory · Physics 2020-09-16 David L. -J. Ho , Arttu Rajantie

It was recently shown that the vanishing of the Coulomb field related to the electric charge of a black hole by virtue of a tiny but non-vanishing photon mass can produce an electric asymmetry in the universe. This process can have place…

High Energy Physics - Phenomenology · Physics 2007-05-23 Diego N. Pelliccia

The ingredients required to create a magnetic field in the early Universe are identified, and compared with Sakharov's conditions for baryogenesis. It is also shown that a long range coherent magnetic field is not generated by the classical…

Astrophysics · Physics 2009-10-28 Sacha Davidson

We consider electroweak baryogenesis mediated by embedded domain walls. Embedded domain walls originating from a symmetry breaking phase transition are stabilized by thermal plasma effects, so that the electroweak symmetry is unbroken in…

High Energy Physics - Phenomenology · Physics 2008-11-26 Robert H. Brandenberger , Wessyl Kelly , Masahide Yamaguchi

Astrophysical objects with negligible resistivity are often threaded by large scale magnetic fields. The generation of these fields is somewhat mysterious, since a magnetic field in a perfectly conducting fluid cannot change the flux…

Astrophysics · Physics 2007-05-23 E. T. Vishniac , A. Lazarian , J. Cho

We propose a novel mechanism to generate primordial magnetic fields (PMFs) strong enough to explain the observed cosmic magnetic fields. We employ a scalar field charged under U(1) gauge symmetry with a non-trivial VEV to provide an…

High Energy Physics - Phenomenology · Physics 2025-11-26 Alexander Ganz , Chunshan Lin , Mian Zhu

We study the generation of magnetic fields during the stage of particle production resulting from spinodal instabilities during phase transitions out of equilibrium. The main premise is that long-wavelength instabilities that drive the…

High Energy Physics - Phenomenology · Physics 2009-11-07 D. Boyanovsky , H. J de Vega , M. Simionato

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

Recent gamma-ray observations of TeV blazars exhibits the deficits of the secondary GeV cascade photons. This suggests the existence of the intergalactic magnetic fields, which may have a primordial origin. One of the mechanisms that can…

High Energy Physics - Phenomenology · Physics 2018-11-16 Kohei Kamada

We analyse solutions of the MHD equations around the electroweak transition taking into account the effects of the chiral anomaly. It is shown that a transition that is not of the first order has direct consequences on the evolution of the…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-17 Petar Pavlović , Natacha Leite , Günter Sigl

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

This letter concentrates on the non-equilibrium evolution of magnetic field structures at the onset of recombination, when the charged particle current densities decay as neutrals are formed. We consider the effect that a decaying magnetic…

Astrophysics · Physics 2009-11-13 Declan A. Diver , Luis F. A. Teodoro

Helical intergalactic magnetic fields at the $\sim 10^{-14}~{\rm G}$ level on $\sim 10~{\rm Mpc}$ length scales are indicated by current gamma ray observations. The existence of magnetic fields in cosmic voids and their non-trivial helicity…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 Tanmay Vachaspati

Primordial magnetic fields generated in the early universe are subject of considerable investigation, and observational limits on their strength are required to constrain the theory. Due to their impact on the reionization process, the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Dominik R. G. Schleicher , Francesco Miniati

We search for observational signatures of magnetic helicity in data from all-sky radio polarization surveys of the Milky Way Galaxy. Such a detection would help confirm the dynamo origin of the field and may provide new observational…

Astrophysics of Galaxies · Physics 2020-10-14 J. L. West , R. N. Henriksen , K. Ferrière , A. Woodfinden , T. Jaffe , B. M. Gaensler , J. A. Irwin