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In astrophysics, turbulent diffusion is often used in place of microphysical diffusion to avoid resolving the small scales. However, we expect this approach to break down when time and length scales of the turbulence become comparable with…

Solar and Stellar Astrophysics · Physics 2014-09-05 M. S. Väisälä , A. Brandenburg , Dhrubaditya Mitra , P. J. Käpylä , M. J. Mantere

Bearing in mind the application to core-collapse supernovae, we study nonlinear properties of the magneto-rotational instability (MRI) by means of three- dimensional simulations in the framework of a local shearing box approximation. By…

Solar and Stellar Astrophysics · Physics 2015-06-11 Y. Masada , T. Takiwaki , K. Kotake , T. Sano

Accretion disks in which angular momentum transport is dominated by the magnetorotational instability (MRI) can also possess additional, purely hydrodynamic, drivers of turbulence. Even when the hydrodynamic processes, on their own,…

Astrophysics · Physics 2009-11-13 Jared C. Workman , Philip J. Armitage

The nonlinear evolution of the magnetorotational instability (MRI) in weakly ionized accretion disks, including the effect of the Hall term and ohmic dissipation, is investigated using local three-dimensional MHD simulations and various…

Astrophysics · Physics 2009-11-07 Takayoshi Sano , James M. Stone

We venture for the comparison between growth rates for magnetorotational instability (MRI) and hydrodynamics instability in the presence of an extra force in the local Keplerian accretion flow. The underlying model is described by the…

High Energy Astrophysical Phenomena · Physics 2022-05-27 Subham Ghosh , Banibrata Mukhopadhyay

Magnetorotational instability (MRI) in a convectively-stable layer around the neutrinosphere is simulated by a three-dimensional model of supernova core. To resolve MRI-unstable modes, a thin layer approximation considering only the radial…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Youhei Masada , Tomoya Takiwaki , Kei Kotake

We determine how MRI-turbulent stresses depend on gas pressure via a suite of unstratified shearing box simulations. Earlier numerical work reported only a very weak dependence at best, results that call into question the canonical…

High Energy Astrophysical Phenomena · Physics 2015-11-11 Johnathan Ross , Henrik N. Latter , Jerome Guilet

Using local 3D MHD simulations, we investigate ways in which galactic turbulence associated with the magnetorotational instability (MRI) may influence the formation and properties of GMCs. Our disk models are vertically stratified and…

Astrophysics · Physics 2009-11-10 Woong-Tae Kim , Eve C. Ostriker , James M. Stone

The outer protoplanetary disks (PPDs) can be subject to the magnetorotational instability (MRI) and the vertical shear instability (VSI). While both processes can drive turbulence in the disk, existing numerical simulations have studied…

Earth and Planetary Astrophysics · Physics 2022-09-21 Can Cui , Xue-Ning Bai

The evolution of warped disks is governed by internal, oscillatory shear flows driven by their distorted geometry. However, these flows are known to be vigorously unstable to a hydrodynamic parametric instability. In many warped systems,…

Solar and Stellar Astrophysics · Physics 2025-08-25 Callum W. Fairbairn , James M. Stone

(abriged) MRI turbulence is a leading mechanism for the generation of an efficient turbulent transport of angular momentum in an accretion disk through a turbulent viscosity effect. It is believed that the same process could also transport…

High Energy Astrophysical Phenomena · Physics 2016-12-07 G. Lesur , P-Y. Longaretti

The effect of large magnetic Prandtl number $\text{Pm}$ (the ratio of viscosity to resistivity) on the turbulent transport and energetics of the magnetorotational instability (MRI) is poorly understood, despite the realization of this…

High Energy Astrophysical Phenomena · Physics 2022-09-28 Loren E. Held , George Mamatsashvili

We study the role of ambipolar diffusion (AD) on the non-linear evolution of the MRI in protoplanetary disks using the strong coupling limit, which applies when the electron recombination time is much shorter than the orbital time. The…

Earth and Planetary Astrophysics · Physics 2015-05-27 Xue-Ning Bai , James M. Stone

The saturation level of the magnetorotational instability (MRI) is investigated using three-dimensional MHD simulations. The shearing box approximation is adopted and the vertical component of gravity is ignored, so that the evolution of…

Astrophysics · Physics 2009-11-10 Takayoshi Sano , Shu-ichiro Inutsuka , Neal J. Turner , James M. Stone

This paper reports on 3D numerical simulations of dynamics and thermodynamics in the diffuse ISM. Our models are local, account for sheared galactic rotation, magnetic fields, and realistic cooling, and resolve scales ~1-200 pc. This…

Astrophysics · Physics 2009-11-11 Robert A. Piontek , Eve C. Ostriker

The local properties of turbulence driven by the magnetorotational instability (MRI) in rotating, shearing flows are studied in the framework of a shearing-box model. Based on numerical simulations, we propose that the MRI-driven turbulence…

Solar and Stellar Astrophysics · Physics 2015-12-14 Justin Walker , Geoffroy Lesur , Stanislav Boldyrev

The destabilising effect of Hall diffusion in a Keplerian disc allows the MRI to occur for much lower ionisation levels than would otherwise be possible. However, simulations suggest that the consequences for the saturated state are not as…

Earth and Planetary Astrophysics · Physics 2015-05-27 Mark Wardle , Raquel Salmeron

Magnetorotational instability (MRI)-driven turbulence and dynamo phenomena are analyzed using direct statistical simulations. Our approach begins by developing a unified mean-field model that combines the traditionally decoupled problems of…

High Energy Astrophysical Phenomena · Physics 2025-05-07 Tushar Mondal , Pallavi Bhat

The magneto-rotational instability (MRI) is considered to be a promising mechanism to amplify the magnetic field in fast rotating protoneutron stars. In contrast to accretion disks, radial buoyancy driven by entropy and lepton fraction…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Jerome Guilet , Ewald Mueller

Resistivity and viscosity have a significant role in establishing the energy levels in turbulence driven by the magnetorotational instability (MRI) in local astrophysical disk models. This study uses the Athena code to characterize the…

High Energy Astrophysical Phenomena · Physics 2011-02-11 Jacob B. Simon , John F. Hawley
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