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Related papers: Primordial Magnetic Helicity from Stochastic Elect…

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We study the evolution of primordial magnetic fields until the recombination epoch, which is constrained by the conservation of magnetic helicity density if they are maximally helical and by the Hosking integral if they are non-helical. We…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-07 Fumio Uchida , Motoko Fujiwara , Kohei Kamada , Jun'ichi Yokoyama

We study the generation of large scale primordial magnetic fields by a cosmological phase transition during the radiation dominated era. The setting is a theory of N charged scalar fields coupled to an abelian gauge field, that undergoes a…

Astrophysics · Physics 2007-05-23 D. Boyanovsky , H. J. de Vega , M. Simionato

Primordial magnetic fields (PMFs) are possible candidates for explaining the observed magnetic fields in galaxy clusters. Two competing scenarios of primordial magnetogenesis have been discussed in the literature: inflationary and…

Cosmology and Nongalactic Astrophysics · Physics 2023-02-17 Salome Mtchedlidze , Paola Domínguez-Fernández , Xiaolong Du , Wolfram Schmidt , Axel Brandenburg , Jens Niemeyer , Tina Kahniashvili

Despite their ubiquity, the origin of cosmic magnetic fields remains unknown. Various mechanisms have been proposed for their existence including primordial fields generated by inflation, or amplification and injection by compact…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-23 Harley Katz , Sergio Martin-Alvarez , Julien Devriendt , Adrianne Slyz , Taysun Kimm

We revisit the mechanism of primordial magnetogenesis during inflation by taking into account the dynamics of the stochastic noises of the electromagnetic perturbations. We obtain the associated Langevin and Fokker-Planck equations for the…

General Relativity and Quantum Cosmology · Physics 2020-11-18 Alireza Talebian , Amin Nassiri-Rad , Hassan Firouzjahi

The mean value of the normalized current helicity in solar active regions is on the order of 1e-8 1/m, negative in the northern hemisphere, positive in the southern hemisphere. Observations indicate that this helicity has a subsurface…

Astrophysics · Physics 2008-11-26 K. Petrovay , P. Chaterjee , A. Choudhuri

The presence of non-zero helicity in intergalactic magnetic fields (IGMF) has been suggested as a clear signature for their primordial origin. We extend a previous analysis of diffuse Fermi-LAT gamma-ray data from 2.5 to more than 11 years…

High Energy Astrophysical Phenomena · Physics 2020-11-06 M. Kachelriess , B. C. Martinez

Magnetic helicity is a fundamental constraint in both ideal and resistive magnetohydrodynamics. Measurements of magnetic helicity density on the Sun and other stars are used to interpret the internal behaviour of the dynamo generating the…

Solar and Stellar Astrophysics · Physics 2022-11-03 Parag Gupta , Radostin D. Simitev , David MacTaggart

The inverse transfer of magnetic helicity is a fundamental process which may explain large scale magnetic structure formation and sustainement. Until very recently, direct numerical simulations (DNS) of the inverse transfer in…

Plasma Physics · Physics 2024-07-29 Jean-Mathieu Teissier , Wolf-Christian Müller

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

Magnetic helicity, $H$, measures magnetic linkages in a volume. The early theoretical development of helicity focused on magnetically closed systems in $\mathcal{V}$ bounded by $\mathcal{S}$. For magnetically closed systems,…

Solar and Stellar Astrophysics · Physics 2023-09-15 Peter W. Schuck , Mark G. Linton

A primordial stochastic magnetic field will induce temperature and polarization fluctuations in the cosmic microwave background. We outline a calculation of the resulting fluctuation power spectra and present numerical results.

Astrophysics · Physics 2009-10-31 Tina Kahniashvili , Arthur Kosowsky , Andrew Mack , Ruth Durrer

We consider the magnetic helicity balance for the galactic dynamo in the framework of the local dynamo problem, as well as in the no-z model (which includes explicitly the radial distribution of the magnetic fields). When calculating the…

Astrophysics · Physics 2009-11-07 N. Kleeorin , D. Moss , I. Rogachevskii , D. Sokoloff

The feature of the spectrum of primordial magnetic field is studied by using renormalization group analysis in magnetohydrodynamics. Taking account of the renormalized resistivity at the fixed point, we show that the scaling of the typical…

Astrophysics · Physics 2009-10-31 Tetsuya Shiromizu

Primordial magnetic field (PMF) is one of the feasible candidates to explain observed large-scale magnetic fields, for example, intergalactic magnetic fields. We present a new mechanism that brings us information about PMFs on small scales…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-28 Shohei Saga , Hiroyuki Tashiro , Shuichiro Yokoyama

Statistical properties of turbulent magnetic fields in radio-synchrotron sources should imprint on the statistics of polarimetric observables. In search of these imprints, we calculate correlation and cross-correlation functions from a set…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 H. Junklewitz , T. A. Enßlin

We study the instability of magnetic fields in a neutron star core driven by the parity violating part of the electron-nucleon interaction in the Standard Model. Assuming a seed field of the order $10^{12}\thinspace\text{G}$, that is a…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Maxim Dvornikov , Victor B. Semikoz

We study a turbulent helical dynamo in a periodic domain by solving the ideal magnetohydrodynamic (MHD) equations with the FLASH code using the divergence-cleaning eight-wave method and compare our results with direct numerical simulations…

Solar and Stellar Astrophysics · Physics 2020-01-28 Axel Brandenburg , Evan Scannapieco

Relative magnetic helicity is commonly used in solar physics to avoid the well known gauge ambiguity of standard magnetic helicity in magnetically open domains. But its physical interpretation is difficult owing to the invocation of a…

Solar and Stellar Astrophysics · Physics 2026-01-12 Anthony R. Yeates , Gunnar Hornig

The Faraday rotation effect, quantified by the Rotation Measure (RM), is a powerful probe of the large-scale magnetization of the Universe - tracing magnetic fields not only on galaxy and galaxy cluster scales but also in the intergalactic…