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We study the local stability of stratified, differentially-rotating fluids to axisymmetric perturbations in the presence of a weak magnetic field and of finite resistivity, viscosity and heat conductivity. This is a generalization of the…

Astrophysics · Physics 2009-11-10 Kristen Menou , Steven A. Balbus , Henk C. Spruit

In this paper, we develop the analysis of a two-dimensional magnetohydrodynamical configuration for an axially symmetric and rotating plasma (embedded in a dipole like magnetic field), modeling the structure of a thin accretion disk around…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Giovanni Montani , Riccardo Benini

Global axisymmetric stability of viscous, resistive, magnetized Couette flow is re-examined, with the emphasis on flows that would be hydrodynamically stable according to Rayleigh's criterion: opposing gradients of angular velocity and…

Astrophysics · Physics 2009-11-06 Jeremy Goodman , Hantao Ji

The stability of charged particle motion in a uniform magnetic field with an added spatially uniform transverse rotating magnetic field (RMF) is studied analytically. It is found that the stability diagram of a single-particle's orbit…

Plasma Physics · Physics 2024-12-13 E. Palmerduca , H. Qin , S. A. Cohen

The magnetorotational instability (MRI) of differential rotation under the simultaneous presence of axial and azimuthal components of the (current-free) magnetic field is considered. For rotation with uniform specific angular momentum the…

Astrophysics · Physics 2009-11-13 Guenther Ruediger , Manfred Schultz

The magnetorotational instability (MRI) has been suggested to have an important role on the dynamics of accretion disks. We investigate MRI as an alternative way for guiding the plasma from the disk to the funnel flow at the…

High Energy Astrophysical Phenomena · Physics 2012-10-08 S. Dogan , E. R. Pekunlu

We study the linear stability of weakly magnetized differentially rotating plasmas in both collisionless kinetic theory and Braginskii's theory of collisional, magnetized plasmas. We focus on the very weakly magnetized limit that is…

Astrophysics of Galaxies · Physics 2015-06-23 Eliot Quataert , Tobias Heinemann , Anatoly Spitkovsky

Deviations from axial symmetry are necessary to maintain self-sustained MRI-turbulence. We define the parameters region where nonaxisymmetric MRI is excited and study dependence of the unstable modes structure and growth rates on the…

Solar and Stellar Astrophysics · Physics 2016-12-07 L. L. Kitchatinov , G. Ruediger

Magneto-rotational instability (MRI) and gravitational instability (GI) are the two principle routes to turbulent angular momentum transport in accretion disks. Protoplanetary disks may develop both. This paper aims to reinvigorate interest…

Earth and Planetary Astrophysics · Physics 2015-06-19 Min-Kai Lin

The magneto-rotational instability (MRI) is the most likely mechanism for transportation of angular momentum and dissipation of energy within hot, ionized accretion discs. This instability is produced through the interactions of a…

High Energy Astrophysical Phenomena · Physics 2021-12-08 Oscar M. Pimentel , P. Chris Fragile , F. D. Lora-Clavijo , Bridget Ierace , Deepika Bollimpalli

The effect of magnetic shear and shear flow on local gravitationally induced instabilities is investigated. A simple model is constructed allowing for an arbitrary entropy gradient and a shear plasma flow in the Boussinesq approximation. A…

Astrophysics · Physics 2009-11-06 Gregory G. Howes , Steven C. Cowley , James C. McWilliams

We perform a local stability analysis of rotational flows in the presence of a constant vertical magnetic field and an azimuthal magnetic field with a general radial dependence. Employing the short-wavelength approximation we develop a…

Fluid Dynamics · Physics 2014-11-14 Oleg N. Kirillov , Frank Stefani , Yasuhide Fukumoto

We revisit the modal analysis of small perturbations in Keplerian ideal gas flows leading to magneto-rotational instability (MRI) using the non-local approach. We consider the case of constant vertical background magnetic field, as well as…

High Energy Astrophysical Phenomena · Physics 2023-12-19 Nikolay Shakura , Konstantin Postnov , Dmitry Kolesnikov , Galina Lipunova

The saturation mechanism of Magneto-Rotational Instability (MRI) is examined through analytical quasilinear theory and through nonlinear computation of a single mode in a rotating disk. We find that large-scale magnetic field is generated…

High Energy Astrophysical Phenomena · Physics 2011-02-11 F. Ebrahimi , S. C. Prager , D. D. Schnack

Context. Differential rotation has a strong influence on stellar internal dynamics and evolution, notably by triggering hydrodynamical instabilities, by interacting with the magnetic field, and more generally by inducing transport of…

Solar and Stellar Astrophysics · Physics 2018-07-25 Vincent Prat , Stéphane Mathis , Kyle Augustson , François Lignières , Jérôme Ballot , Lucie Alvan , Allan Sacha Brun

The magneto-Rayleigh-Taylor instability (mRTI) is a key process in inertial confinement fusion and is thought to be widespread in the interstellar medium, where it can concentrate plasma into discrete structures. We present resistive MHD…

Fluid Dynamics · Physics 2025-12-25 Xin Bian , Riccardo Betti , Dongxiao Zhao , Hussein Aluie

We calculate the stability of a multiple relaxation region MHD (MRXMHD) plasma, or stepped-Beltrami plasma, using both variational and tearing mode treatments. The configuration studied is a periodic cylinder. In the variational treatment,…

Plasma Physics · Physics 2015-05-13 M. J. Hole , R. Mills , S. R. Hudson , R. L. Dewar

The magnetorotational instability (MRI) is a crucial mechanism of angular momentum transport in a variety of astrophysical accretion disks. In systems accreting at well below the Eddington rate, such as the central black hole in the Milky…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Mario A. Riquelme , Eliot Quataert , Prateek Sharma , Anatoly Spitkovsky

The dynamics of the oscillator system is investigated. The conditions under which this dynamics becomes unstable are determined. In particular, it is shown that plasma in constant magnetic field becomes unstable if its density exceeds a…

Plasma Physics · Physics 2019-04-23 Vyacheslav Buts

Magnetars are highly magnetized neutron stars whose magnetic dipole ranges from $10^{14}$ to $10^{15}$ G. The MRI is considered to be a promising mechanism to amplify the magnetic field in fast-rotating protoneutron stars and form…

High Energy Astrophysical Phenomena · Physics 2021-01-27 Alexis Reboul-Salze , Jérôme Guilet , Raphaël Raynaud , Matteo Bugli