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We study the asymptotic properties of a stochastic model for the induction equations of the magnetic field in a three dimensional periodic domain. The turbulent velocity field driving the electromotive force on the magnetic field is modeled…

Probability · Mathematics 2025-06-04 Federico Butori , Eliseo Luongo

Stochastic perturbations of transport type are a common and widely accepted way of representing turbulent effects in fluid dynamics models. In many known examples, it even leads to improved solution theory, a phenomenon known as…

Analysis of PDEs · Mathematics 2025-11-19 Federico Butori , Avi Mayorcas , Silvia Morlacchi

We have extended our previous mean-field galactic dynamo model which included algebraic and dynamic alpha nonlinearities (Kleeorin et al., A&A, v. 387, 453, 2002), to include also a quenching of turbulent diffusivity. We readily obtain…

Astrophysics · Physics 2014-10-13 N. Kleeorin , D. Moss , I. Rogachevskii , D. Sokoloff

We present and analyze a simplified stochastic $\alpha \Omega -$dynamo model which is designed to assess the influence of additive and multiplicative noises, non-normality of dynamo equation, and nonlinearity of the $\alpha -$% effect and…

Astrophysics · Physics 2009-11-10 Sergei Fedotov , Irina Bashkirtseva , Lev Ryashko

We study an example of instability in presence of a multiplicative noise, namely the spontaneous generation of a magnetic field in a turbulent medium. This so-called turbulent dynamo problem remains challenging, experimentally and…

Astrophysics · Physics 2016-08-16 Nicolas Leprovost , Bérengère Dubrulle

A recent paper of Melbourne & Stuart, A note on diffusion limits of chaotic skew product flows, Nonlinearity 24 (2011) 1361-1367, gives a rigorous proof of convergence of a fast-slow deterministic system to a stochastic differential…

Dynamical Systems · Mathematics 2015-06-15 Georg A. Gottwald , Ian Melbourne

It was shown in arXiv:0810.4094 [hep-th] that in the presence of the magnetic field the sound waves in (2+1) dimensional plasma disappear and are replaces by a diffusive mode. Similarly, the shear and charge diffusion fluctuations form a…

High Energy Physics - Theory · Physics 2009-11-19 Evgeny I. Buchbinder , Alex Buchel

Our attention focuses on the stochastic dynamo equation with non-normal operator that give an insight into the role of stochastics and non-normality in the galactic magnetic field generation. The main point of this Letter is a discussion of…

Astrophysics · Physics 2009-11-07 Sergei Fedotov

A linear stochastic vector advection equation is considered; the equation may model a passive magnetic field in a random fluid. When the driving velocity field is rough but deterministic, in particular just H\"{o}lder continuous and…

Probability · Mathematics 2015-06-18 Franco Flandoli , Mario Maurelli , Mikhail Neklyudov

We formulate a solvable model that describes generation and saturation of mean magnetic field in a dynamo with kinetic helicity, in the limit of large magnetic Prandtl number. This model is based on the assumption that the stochastic part…

Astrophysics · Physics 2009-11-06 Stanislav Boldyrev

We consider mean-field dynamo models with fluctuating \alpha effect, both with and without shear. The \alpha effect is chosen to be Gaussian white noise with zero mean and given covariance. We show analytically that the mean magnetic field…

Solar and Stellar Astrophysics · Physics 2013-06-28 Dhrubaditya Mitra , Axel Brandenburg

We investigate the asymptotic behaviour of a reduced {\alpha}{\Omega}-dynamo model of magnetic field generation in spiral galaxies where fluctuation in the {\alpha}-effect results in a system with state-dependent stochastic perturbations.…

Dynamical Systems · Mathematics 2016-06-15 Cónall Kelly

Driven Langevin processes have appeared in a variety of fields due to the relevance of natural phenomena having both deterministic and stochastic effects. The stochastic currents and fluxes in these systems provide a convenient set of…

Chemical Physics · Physics 2017-01-04 Michael J. Catanzaro , Vladimir Y. Chernyak , John R. Klein

We study large-scale kinematic dynamo action of steady mirror-antisymmetric flows of incompressible fluid, that involve small spatial scales only, by asymptotic methods of the multiscale stability theory. It turns out that, due to the…

Fluid Dynamics · Physics 2019-08-13 Alexander Andrievsky , Roman Chertovskih , Vladislav Zheligovsky

We investigate magnetic field amplification in a turbulent velocity field with nonzero helicity, in the framework of the kinematic Kazantsev-Kraichnan model. We present the numerical solution of the model for the practically important case…

Astrophysics · Physics 2010-11-11 Leonid Malyshkin , Stanislav Boldyrev

We consider the problem of sliding motion of a charge-density-wave subject to static disorder within an elastic medium model. Starting with a field-theoretical formulation, which allows exact disorder averaging, we propose a self-consistent…

Disordered Systems and Neural Networks · Physics 2009-10-30 C. R. Werner , U. Eckern

We introduce a stochastic version of Proudman-Taylor model, a 2D-3C fluid approximation of the 3D Navier-Stokes equations, with the small-scale turbulence modeled by a transport-stretching noise. For this model we may rigorously take a…

Probability · Mathematics 2024-06-12 Franco Flandoli , Dejun Luo

This paper establishes the long time asymptotic limit of the three dimensional Vlasov-Poisson equation with strong external magnetic field. The guiding center approximation is investigated in the three dimensional case with a non-constant…

Analysis of PDEs · Mathematics 2016-11-23 Pierre Degond , Francis Filbet

The stochastic thin-film equation with mobility exponent $n\in [\frac{8}{3},3)$ on the one-dimensional torus with multiplicative Stratonovich noise is considered. We show that martingale solutions exist for non-negative initial values. This…

Analysis of PDEs · Mathematics 2024-11-01 Konstantinos Dareiotis , Benjamin Gess , Manuel V. Gnann , Max Sauerbrey

We study the three-dimensional stochastic electron magnetohydrodynamics (EMHD) system with fractional dissipation on the torus, driven by Stratonovich transport noise acting through divergence-free first-order operators. The noise generates…

Probability · Mathematics 2026-04-10 Ruimeng Hu , Qirui Peng , Xu Yang
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