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Faraday rotation induced B-modes can provide a distinctive signature of primordial magnetic fields because of their characteristic frequency dependence and because they are only weakly damped on small scales, allowing them to dominate…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-29 Levon Pogosian , Amit P. S. Yadav , Yi-Fung Ng , Tanmay Vachaspati

Primordial magnetic fields (PMFs), being present before the epoch of cosmic recombination, induce small-scale baryonic density fluctuations. These inhomogeneities lead to an inhomogeneous recombination process that alters the peaks and…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-12 Karsten Jedamzik , Andrey Saveliev

Perturbations to the cosmic baryon density - and thus to the total-matter density - can be induced by magnetohydronamic forces if there are primordial magnetic fields. The power spectrum for these density perturbations was first provided in…

Cosmology and Nongalactic Astrophysics · Physics 2023-09-08 Tal Adi , Hector Cruz , Marc Kamionkowski

The origin of large-scale magnetic fields is an unsolved problem in cosmology. In order to overcome, a possible scenario comes from the idea that these fields emerged from a small primordial magnetic field (PMF), produced in the early…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-15 Hector J. Hortua , Leonardo Castañeda

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…

Primordial magnetic fields (PMFs) play a pivotal role in influencing small-scale fluctuations within the primordial density field, thereby enhancing the matter power spectrum within the context of the $\Lambda$CDM model at small scales.…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-02 Qile Zhang , Shang Li , Xiu-Hui Tan , Jun-Qing Xia

In this thesis, we aim to investigate the mechanisms underlying the genesis of magnetic fields in the Universe and explore their potential in addressing the matter-antimatter asymmetry. We construct consistent models that generate the…

General Relativity and Quantum Cosmology · Physics 2024-03-21 Ashu Kushwaha

Magnetic fields are present on all scales in the Universe. While we understand the processes which amplify the fields fairly well, we do not have a "natural" mechanism to generate the small initial seed fields. By using fully relativistic…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-18 Ellie Nalson , Adam J. Christopherson , Karim A. Malik

We consider that no mean magnetic field exists during this epoch, but that there is a mean magnetic energy associated with large-scale magnetic inhomogeneities. We study the evolution of these inhomogeneities and their influence on the…

Astrophysics · Physics 2009-01-14 E. Battaner , E. Florido , J. Jimenez-Vicente

From previous studies of the effect of primordial magnetic fields on early structure formation, we know that the presence of primordial magnetic fields during early structure formation could induce more perturbations at small scales (at…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Kanhaiya L. Pandey , Shiv K. Sethi

Primordial magnetic fields possibly generated in the very early universe are one of the candidates for the origin of magnetic fields observed in many galaxies and galaxy clusters. After recombination, the dissipation process of the…

Astrophysics · Physics 2009-11-11 Hiroyuki Tashiro , Naoshi Sugiyama

The origin of our universe's cosmological magnetic fields remains a mystery. In this study, we consider whether these magnetic fields could have been generated in the early universe by a population of charged, spinning primordial black…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-31 Dan Hooper , Aurora Ireland , Gordan Krnjaic

We present the first constraints on primordial magnetic fields from the Lyman-$\alpha$ forest using full cosmological hydrodynamic simulations. At the scales and redshifts probed by the data, the flux power spectrum is extremely sensitive…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-29 Mak Pavičević , Vid Iršič , Matteo Viel , James Bolton , Martin G. Haehnelt , Sergio Martin-Alvarez , Ewald Puchwein , Pranjal Ralegankar

Magnetic fields are observed on nearly all scales in the universe, from stars and galaxies upto galaxy clusters and even beyond. The origin of cosmic magnetic fields is still an open question, however a large class of models puts its origin…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-19 Kerstin E. Kunze

We describe a technique for using simulated tensor perturbations in order to place upper limits on the intensity of magnetic fields in the early universe. As an example, we apply this technique to the beginning of primordial…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-09 David Garrison

We show that the presence of primordial stochastic (hypercharge) magnetic fields before the electroweak (EW) phase transition induces isocurvature fluctuations (baryon number inhomogeneities). Depending on the details of the magnetic field…

High Energy Physics - Phenomenology · Physics 2009-12-15 M. Giovannini , M. E. Shaposhnikov

We study the effect of primordial magnetic fields (PMFs) on the anisotropies of the cosmic microwave background (CMB). We assume the spectrum of PMFs is described by log-normal distribution which has a characteristic scale, rather than…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-30 Dai G. Yamazaki , Kiyotomo Ichiki , Keitaro Takahashi

The observed galactic magnetic fields may have a primordial origin. I briefly review the observations, their interpretation in terms of the dynamo theory, and the current limits on cosmological magnetic fields. Several possible mechanisms…

Astrophysics · Physics 2007-05-23 Kari Enqvist

Galactic magnetic fields are observed of order $\sim 10^{-6}G$, but their origin is not definitely known yet. In this paper we consider the primordial magnetic fields generated in the early universe and analyse their effects on the density…

Astrophysics · Physics 2016-08-30 Seoktae Koh , Chul H. Lee

We derive an upper limit of $B_0<3.4\times 10^{-9}(\Omega_0h_{50}^2)^{1/2}$ Gauss on the present strength of any primordial homogeneous magnetic field. The microwave background anisotropy created by cosmological magnetic fields is…

Astrophysics · Physics 2016-08-30 John D. Barrow , Pedro G. Ferreira , Joseph Silk