English
Related papers

Related papers: Magnetic fields in the first galaxies: Dynamo ampl…

200 papers

Primordial magnetic fields (PMFs) enhance small-scale structure formation through the Lorentz force acting on baryons, boosting the abundance of low-mass halos and their hosted galaxies. We show that the reionisation history calibrated with…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-29 Malcolm Fairbairn , María Olalla Olea-Romacho , Juan Urrutia , Ville Vaskonen

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

In this talk I discuss the non-linear development of magnetic fields in the early universe. I very briefly mention a number of particle physics mechanisms for generating magnetic fields in the early universe, but the emphasis is on a review…

High Energy Physics - Phenomenology · Physics 2009-09-25 P. Olesen

We have performed magnetohydrodynamical simulations to study the amplification of magnetic fields in the precursors of shock waves. Strong magnetic fields are required in the precursors of the strong shocks that occur in supernova remnants.…

High Energy Astrophysical Phenomena · Physics 2015-06-17 M. Bruggen

The potential importance of magnetic fields during structure formation and gravitational collapse in the early Universe has been shown in several studies. In particular, magnetic field amplification by the small-scale dynamo plays an…

Astrophysics of Galaxies · Physics 2024-01-09 V. B. Díaz , D. R. G. Schleicher , M. A. Latif , P. Grete , R. Banerjee

Natural dynamos such as planets and stars generate global scale magnetic field despite the inferred presence of small scale turbulence. Such systems are known as large scale dynamos and are typically driven by convection and influenced by…

Fluid Dynamics · Physics 2022-02-24 Ming Yan , Michael A. Calkins

We investigate the generation of large scale magnetic fields in the universe from quantum fluctuations produced in the inflationary stage. By coupling these quantum fluctuations to the dilaton field and Ricci scalar, we show that the…

Astrophysics · Physics 2008-11-26 A. Akhtari Zavareh , A. Hojjati , B. Mirza

Magnetic fields are generated in ionized objects rotating with respect to a radiation background. Based on conservation of canonical ion momentum, it has been previously suggested that even if the radiation intensity is unrestricted the…

Astrophysics · Physics 2009-11-10 L. Chuzhoy

Aims. We investigate the cosmological evolution of large- and small-scale magnetic fields in galaxies in the light of present models of formation and evolution of galaxies. Methods. We use the dynamo theory to derive the timescales of…

Astrophysics · Physics 2009-11-13 Tigran G. Arshakian , Rainer Beck , Marita Krause , Dmitry Sokoloff

We discuss the evolution of cosmological magnetic fields from the early universe to the present. We review different scenarios for magnetogenesis in the early universe and follow the subsequent evolution of these fields as the universe…

Astrophysics · Physics 2007-05-23 Angela V. Olinto

We study the possibility of generating magnetic fields during the evolution of electron, proton, and photon plasma in the pre-recombination era. We show that a small magnetic field can be generated in the second order of perturbation theory…

Astrophysics · Physics 2009-11-10 Rajesh Gopal , Shiv Sethi

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

The role of magnetic fields in the multi-phase interstellar medium (ISM) is explored using magnetohydrodynamic (MHD) simulations that include energy injection by supernova (SN) explosions and allow for dynamo action. Apart from providing…

Astrophysics of Galaxies · Physics 2018-10-03 A. Shukurov , C. C. Evirgen , A. Fletcher , P. J. Bushby , F. A. Gent

While magnetic fields are important in contemporary star formation, their role in primordial star formation is unknown. Magnetic fields of order 10^-16 G are produced by the Biermann battery due to the curved shocks and turbulence…

Astrophysics of Galaxies · Physics 2020-07-15 Christopher F. McKee , Athena Stacy , Pak Shing Li

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

Magnetic fields are widely observed in the Universe in virtually all astrophysical objects, from individual stars to entire galaxies, even in the intergalactic medium, but their specific generation has long been debated. Due to the…

Astrophysics of Galaxies · Physics 2017-11-08 Michael Rieder , Romain Teyssier

We present the first study on the amplification of magnetic fields by the turbulent dynamo in the highly subsonic regime, with Mach numbers ranging from $10^{-3}$ to $0.4$. We find that for the lower Mach numbers the saturation efficiency…

High Energy Astrophysical Phenomena · Physics 2021-03-04 Radhika Achikanath Chirakkara , Christoph Federrath , Pranjal Trivedi , Robi Banerjee

Magnetic fields in galaxies and galaxy clusters are amplified from a very weak seed value to the observed $\mu{\rm G}$ strengths by the turbulent dynamo. The seed magnetic field can be of primordial or astrophysical origin. The strength and…

Astrophysics of Galaxies · Physics 2020-10-07 Amit Seta , Christoph Federrath

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

The magnetic helicity has paramount significance in nonlinear saturation of galactic dynamo. We argue that the magnetic helicity conservation is violated at the lepton stage in the evolution of early Universe. As a result, a cosmological…

Astrophysics · Physics 2009-11-10 V. B. Semikoz , D. D. Sokoloff