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It is shown that small-scale magnetic fields present before recombination induce baryonic density inhomogeneities of appreciable magnitude. The presence of such inhomogeneities changes the ionization history of the Universe, which in turn…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Karsten Jedamzik , Tom Abel

Weak magnetic fields must have existed in the early Universe, as they were sourced by the cross product of electron density and temperature gradients through the Biermann-battery mechanism. In this paper we calculate the magnetic fields…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-15 Nanoom Lee , Yacine Ali-Haimoud

Large scale magnetic fields seem to be present in almost all astrophysical systems and scales from planets to superclusters of galaxies and in very low density intergalactic media. The upper limit of primordial magnetic fields (PMF) has…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-26 Anwar Saleh AlMuhammad

In this paper, we investigate the effects of helical primordial magnetic fields (PMFs) on the cosmic microwave background (CMB) reduced bispectrum. We derive the full three-point statistics of helical magnetic fields and numerically…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-13 Hector J. Hortua , Leonardo Castañeda

We explore the ways in which primordial magnetic fields influence the thermal and ionization history of the post-recombination universe. After recombination the universe becomes mostly neutral resulting also in a sharp drop in the radiative…

Astrophysics · Physics 2008-11-26 Shiv K. Sethi , Kandaswamy Subramanian

The amplification of the primordial magnetic fields and the gravitational baryogenesis, a mechanism that allows to generate the baryon asymmetry in the Universe by means of the coupling between the Ricci scalar curvature and the baryon…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-18 Herman J. Mosquera Cuesta , Gaetano Lambiase

Magnetic field plays a very important role in many astronomical phenomena at various scales of the universe. It is no exception in the early universe. Since the energy density, pressure, and tension of the primordial magnetic field affect…

Astrophysics · Physics 2009-11-11 Dai G. Yamazaki , Kiyotomo Ichiki , Ken-ichi Umezu , Hidekazu Hanayama

The redshifted cosmic 21 cm line signal of neutral hydrogen provides the possibility to constrain the matter power spectrum. Cross correlating temperature maps at different frequencies (corresponding to different redshifts along the line of…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-20 Kerstin E. Kunze

We investigate hydromagnetic turbulence of primordial magnetic fields using magnetohydrodynamics (MHD) in an expanding universe. We present the basic, covariant MHD equations, find solutions for MHD waves in the early universe, and…

Astrophysics · Physics 2014-10-13 Axel Brandenburg , Kari Enqvist , Poul Olesen

We discuss whether an unaccounted contribution to the Cosmic Microwave Background polarization $B$-mode by primordial magnetic fields (PMFs) can bias future constraints on inflationary gravitational waves. As a case-study, we consider a…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-05 Fabrizio Renzi , Giovanni Cabass , Eleonora Di Valentino , Alessandro Melchiorri , Luca Pagano

The magneto-hydrodynamic decay of primordial magnetic fields can distort the black-body spectrum of the cosmic microwave background (CMB) by draining magnetic energy into thermal plasmas and photons. The current limits on CMB distortion…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-24 Fumio Uchida , Kohei Kamada , Hiroyuki Tashiro

We study the impact of a stochastic background of primordial magnetic fields on the scalar contribution of CMB anisotropies and on the matter power spectrum. We give the correct initial conditions for cosmological perturbations and the…

Astrophysics · Physics 2008-12-18 Fabio Finelli , Francesco Paci , Daniela Paoletti

The coupling of photons and baryons by Thomson scattering in the early universe imprints features in both the Cosmic Microwave Background (CMB) and matter power spectra. The former have been used to constrain a host of cosmological…

Astrophysics · Physics 2008-11-26 Martin White

The presence of magnetic fields in the early universe affects the cosmological processes, leading to the distinct signature, which allows constraining their properties and the genesis mechanisms. In this study, we revisit the method to…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-13 Ashu Kushwaha , Teruaki Suyama

The presence of ubiquitous magnetic fields in the universe is suggested from observations of radiation and cosmic ray from galaxies or the intergalactic medium (IGM). One possible origin of cosmic magnetic fields is the magnetogenesis in…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-27 Teppei Minoda , Kenji Hasegawa , Hiroyuki Tashiro , Kiyotomo Ichiki , Naoshi Sugiyama

Most of the baryonic matter in the Universe is permeated by magnetic fields which affect many, if not most, of astrophysical phenomena both, in compact sources and in diffuse gas. Recent years have been marked by a worldwide surge of…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-23 Elisabete M. de Gouveia Dal Pino

Primordial magnetic fields could provide an explanation for the galactic magnetic fields observed today, in which case they may also leave interesting signals in the CMB and the small-scale matter power spectrum. We discuss how to…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-26 J. Richard Shaw , Antony Lewis

Primordial magnetic fields (PMFs) can source gravitational wave background (GWB). In this paper, we investigate the possible constraints on small-scale PMF considering the ongoing and forthcoming direct detection observations of GWB. In…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-18 Shohei Saga , Hiroyuki Tashiro , Shuichiro Yokoyama

There are at present more then 30 theories about the origin of cosmic magnetic fields at galactic and intergalactic scales. Most of them rely on concepts of elementary particle physics, like phase transitions in the early Universe, string…

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

A symmetry-breaking phase transition in the early universe could have led to the formation of cosmic defects. Because these defects dynamically excite not only scalar and tensor type cosmological perturbations but also vector type ones,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Kouichirou Horiguchi , Kiyotomo Ichiki , Toyokazu Sekiguchi , Naoshi Sugiyama