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We discuss how a cosmological magnetic field could affect the expansion of the universe, through its interaction with the spacetime geometry. The tension of the field lines means that the magneto-curvature coupling tends to accelerate…

Astrophysics · Physics 2009-10-31 D. R. Matravers , C. G. Tsagas

Understanding the origin and evolution of magnetic fields on cosmological scales opens up a window into the physics of the early Universe. Numerical simulations of such fields require a careful treatment to faithfully solve the equations of…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-28 Nikyta Shchutskyi , Matthieu Schaller , Orestis A. Karapiperis , Federico A. Stasyszyn , Axel Brandenburg

Measuring the magnetic field in cosmic filaments reveals how the Universe is magnetised and the process that magnetised it. Using the Rotation Measures (RM) at 144-MHz from the LoTSS DR2 data, we analyse the rms of the RM extragalactic…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-26 E. Carretti , S. O'Sullivan , V. Vacca , F. Vazza , C. Gheller , T. Vernstrom , A. Bonafede

Massive stars are crucial building blocks of galaxies and the universe, as production sites of heavy elements and as stirring agents and energy providers through stellar winds and supernovae. The field of magnetic massive stars has seen…

Solar and Stellar Astrophysics · Physics 2015-05-27 Rolf Walder , Doris Folini , Georges Meynet

We investigate the evolution of magnetic fields generated by the crystallization-driven dynamo in carbon-oxygen white dwarfs (WDs) with masses $\lesssim1.05\ M_{\odot}$. We use scalings for the dynamo to demonstrate that the initial…

Solar and Stellar Astrophysics · Physics 2024-10-31 Matias Castro-Tapia , Shu Zhang , Andrew Cumming

Dynamo action is shown to be induced from homogeneous non-minimal photon-torsion axial coupling in the quantum electrodynamics (QED) framework in Riemann flat spacetime contortion decays. The geometrical optics in Riemann-Cartan spacetime…

General Relativity and Quantum Cosmology · Physics 2010-07-13 Garcia de Andrade

It is demonstrated that strong magnetic fields are produced from a zero initial magnetic field during the pregalactic era, when galaxies are first forming. Their development proceeds in three phases. In the first phase, weak magnetic fields…

Astrophysics · Physics 2011-02-11 Russell M. Kulsrud , Renyue Cen , Jeremiah P. Ostriker , Dongsu Ryu

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

Recently Shukurov et al [Phys Rev E 72, 025302 (2008)], made use of non-orthogonal curvilinear coordinate system on a dynamo Moebius strip flow, to investigate the effect of stretching by a turbulent liquid sodium flow. In plasma physics,…

Mathematical Physics · Physics 2009-06-22 Garcia de Andrade

The small-scale kinematic dynamo in a two-dimensional chaotic flow is studied. The analytic approach is developed in framework of the Kraichnan-Kazantsev model. It is shown that the growth of magnetic field $\bm{B}$ fluctuations stops at…

Chaotic Dynamics · Physics 2016-03-30 Igor Kolokolov

Observations indicate that intergalactic magnetic fields have amplitudes of the order of $\sim 10^{-6}$ G and are uniform on scales of $\sim 10$ kpc. Despite their wide presence in the Universe, their origin remains an open issue. Even by…

General Relativity and Quantum Cosmology · Physics 2022-10-26 S. Capozziello , A. Carleo , G. Lambiase

Investigation of the eigenvalue spectra of dynamo solutions, has been proved fundamental for the knowledge of dynamo physics. Earlier, curvature-folding relation on dynamos in Riemannian spaces has been investigated [PPL 2008]. Here,…

Mathematical Physics · Physics 2010-04-16 L. C. Garcia de Andrade

It is shown that the existence of the cosmic kinematic fast dynamos in Bianchi type IX rotating cosmological models, faces severe difficulties, due to the fact that in these models rotation increases without bounds, which is strictly…

Astrophysics · Physics 2007-07-23 Garcia de Andrade

We study the evolution of primordial magnetic fields in an expanding cosmic plasma. For this purpose we present a comprehensive theoretical model to consider the evolution of MHD turbulence that can be used over a wide range of physical…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-12 Tina Kahniashvili , Axel Brandenburg , Alexander G. Tevzadze

Cosmic kinematic fast dynamo is found in non-inflationary phases of an ellipsoidal anisotropic cosmological metric background solution of Einstein field equations of general relativity. The magnetic field is amplified inside the universe…

General Relativity and Quantum Cosmology · Physics 2007-07-13 L. C. Garcia de Andrade

We study primordial magnetic field effects on the matter perturbations in the Universe. We assume magnetic field generation prior to the big bang nucleosynthesis (BBN), i.e. during the radiation dominated epoch of the Universe expansion,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Tina Kahniashvili , Yurii Maravin , Aravind Natarajan , Nicholas Battaglia , Alexander G. Tevzadze

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

Galaxies are observed to host magnetic fields with a typical total strength of around 15microgauss. A coherent large-scale field constitutes up to a few microgauss of the total, while the rest is built from strong magnetic fluctuations over…

Astrophysics of Galaxies · Physics 2024-01-09 Maarit J. Korpi-Lagg , Mordecai-Mark Mac Low , Frederick A. Gent

Boozer addressed the role of magnetic helicity in dynamos [Phys Fluids \textbf{B},(1993)]. He pointed out that the magnetic helicity conservation implies that the dynamo action is more easily attainable if the electric potential varies over…

Plasma Physics · Physics 2009-11-23 Garcia de Andrade

(abridged) A detailed examination of the evolution of stochastic magnetic fields between high cosmic temperatures and the present epoch is presented. A simple analytical model matching the results of the 3D MHD simulations allows for the…

Astrophysics · Physics 2009-11-10 Robi Banerjee , Karsten Jedamzik