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Related papers: Cylindrical anisotropic $\alpha^{2}$ dynamos

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We carried out global three-dimensional magneto-hydrodynamic simulations of dynamo activities in galactic gaseous disks without assuming equatorial symmetry. Numerical results indicate the growth of azimuthal magnetic fields non-symmetric…

Astrophysics of Galaxies · Physics 2015-06-12 Mami Machida , Kenji E. Nakamura , Takahiro Kudoh , Takuya Akahori , Sofue Yoshiaki , Ryoji Matsumoto

We analyze direct numerical simulations of large-scale dynamos in inhomogeneous nonhelically driven rotating turbulence with and without shear. The forcing is modulated so that the turbulent intensity peaks in the middle of the…

Plasma Physics · Physics 2025-05-02 Axel Brandenburg , Ethan T. Vishniac

We study how anisotropy of turbulent convection affects diffusion of large-scale magnetic fields and the dynamo process on the Sun. The effect of anisotropy is calculated in a mean-field magneto-hydrodynamics framework using the minimal…

Solar and Stellar Astrophysics · Physics 2015-06-16 V. V. Pipin , A. G. Kosovichev

The 2D Parker's mean-field dynamo equations with a various distributions of the $\alpha$- and $\omega$-effects are considered. We show that smooth profiles of $\alpha$ and $\omega$ can produce dipole configuration of the magnetic field with…

Fluid Dynamics · Physics 2014-08-25 Maxim Reshetnyak

Observational evidence for dynamo action in spiral galaxies is reviewed, and the capabilities of various theories in explaining the basic features of galactic magnetic fields are discussed. Mean-field dynamo models appear to be unique in…

Astrophysics · Physics 2007-05-23 Anvar Shukurov

The rapid rotation of planets causes cyclonic thermal turbulence in their cores which may generate the large-scale magnetic fields observed outside the planets. We consider the model which enables us reproduce the typical features of…

Fluid Dynamics · Physics 2020-01-29 M. Reshetnyak , P. Hejda

To understand the dynamo driven by time-dependent flow, e.g. turbulence, we investigate numerically the dynamo induced by time-periodic force in rotating magnetohydrodynamic flow and focus on the effect of force frequency on the dynamo…

Fluid Dynamics · Physics 2018-03-14 Xing Wei

The dynamics of domain walls in ultrathin ferromagnetic strips with perpendicular magnetic anisotropy is studied from both numerical and analytical micromagnetics. The influence of the interfacial Dzyaloshinskii-Moriya interaction…

Materials Science · Physics 2016-04-20 L. Sánchez-Tejerina , Ó. Alejos , E. Martínez , J. M. Muñoz

In systems where the standard $\alpha$ effect is inoperative, one often explains the existence of mean magnetic fields by invoking the `incoherent $\alpha$ effect', which appeals to fluctuations of the mean kinetic helicity at a mesoscale.…

Solar and Stellar Astrophysics · Physics 2023-10-24 Kishore Gopalakrishnan , Nishant Singh

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

Densely packed systems of thermal particles in curved geometries are frequently encountered in biological and microfluidic systems. In 2D systems, at sufficiently high surface coverage, diffusive motion is widely known to be strongly…

Statistical Mechanics · Physics 2014-07-22 Remy Kusters , Stefan Paquay , Cornelis Storm

Layered {\alpha}-RuCl3 is a promising material to potentially realize the long-sought Kitaev quantum spin liquid with fractionalized excitations. While evidence of this exotic state has been reported under a modest in-plane magnetic field,…

We report the first experimental observation of reversals of a dynamo field generated in a laboratory experiment based on a turbulent flow of liquid sodium. The magnetic field randomly switches between two symmetric solutions B and -B. We…

We investigate an electromagnetic instability in two-dimensional materials arising from an anisotropy of the Fermi surface, utilizing a kinetic model accounting for the effects of the values of temperature, chemical potential and anisotropy…

Materials Science · Physics 2025-06-27 Diogo Simões , Hugo Terças , Jorge Ferreira

Spectropolarimetric observations show that many low-mass stars possess large-scale poloidal magnetic fields with considerable dipole component, which in some cases exhibit temporal dynamics - cycles or reversals. Although it is widely…

Solar and Stellar Astrophysics · Physics 2025-07-02 Anna Guseva , Ludovic Petitdemange , Charly Pinçon

A magnetic flux tube may be considered both as a separate body and as a confined field. As a field, it is affected both by differential rotation ($\Omega$-effect) and cyclonic convection ($\alpha$-effect). As a body, the tube experiences…

Astrophysics · Physics 2009-11-13 L. H. Li , S. Sofia , G. Belvedere

Here, an analytical version of numerical results is obtained in case of considering the laminar non-turbulent limit, of a twisted Riemannian thin flux tube. It is shown that the magnetic field is amplified, when electric current helicity…

Fluid Dynamics · Physics 2009-06-30 Garcia de Andrade

We supplement the mean field dynamo growth equation with the total magnetic helicity evolution equation. This provides an explicitly time dependent model for alpha quenching in dynamo theory. For dynamos without shear, this approach…

Astrophysics · Physics 2009-11-07 Eric G. Blackman , Axel Brandenburg

We present numerical simulations of three-dimensional compressible magnetoconvection in a rotating rectangular box that represents a section of the solar convection zone. The box contains a convectively unstable layer, surrounded by stably…

Astrophysics · Physics 2009-11-07 M. Ossendrijver , M. Stix , A. Brandenburg

The dynamo effect is a class of macroscopic phenomena responsible for generation and maintaining magnetic fields in astrophysical bodies. It hinges on hydrodynamic three-dimensional motion of conducting gases and plasmas that achieve high…

Strongly Correlated Electrons · Physics 2018-10-31 Victor Galitski , Mehdi Kargarian , Sergey Syzranov
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