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Whether the magnetorotational instability (MRI) can amplify initially weak magnetic fields to dynamically relevant strengths in core collapse supernovae is still a matter of active scientific debate. Recent numerical studies have shown that…

Solar and Stellar Astrophysics · Physics 2016-06-03 Tomasz Rembiasz , Jérôme Guilet , Martin Obergaulinger , Pablo Cerdá-Durán , Miguel-Ángel Aloy , Ewald Müller

The magnetorotational instability (MRI) is considered a key process for driving efficient angular momentum transport in astrophysical disks. Understanding its non-linear saturation constitutes a fundamental problem in modern accretion disk…

High Energy Astrophysical Phenomena · Physics 2012-05-25 Martin E. Pessah

We propose that the strength of angular momentum transport in accretion discs threaded by net vertical magnetic field is determined by a self-regulation mechanism: the magnetorotational instability (MRI) grows until its own turbulent…

High Energy Astrophysical Phenomena · Physics 2023-04-18 Mitchell C. Begelman , Philip J. Armitage

We investigate the stability of incompressible, exact, non-ideal magnetorotational (MRI) modes against parasitic instabilities. Both Kelvin-Helmholtz and tearing-mode parasitic instabilities may occur in the dissipative regimes accessible…

High Energy Astrophysical Phenomena · Physics 2011-02-11 Martin E. Pessah , Jeremy Goodman

(Abriged) The magnetorotational instability (MRI) is believed to be an efficient way to transport angular momentum in accretion discs. It has also been suggested as a way to amplify magnetic fields in discs, the instability acting as a…

Astrophysics · Physics 2009-11-13 G. Lesur , G. I. Ogilvie

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

Angular momentum transport and particle acceleration during the magnetorotational instability (MRI) in a collisionless accretion disk are investigated using three-dimensional particle-in-cell (PIC) simulation. We show that the kinetic MRI…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Masahiro Hoshino

The magnetorotational instability (MRI) can be a powerful mechanism amplifying the magnetic field in core-collapse supernovae. Whether initially weak magnetic fields can be amplified by this instability to dynamically relevant strengths is…

Solar and Stellar Astrophysics · Physics 2016-03-03 Tomasz Rembiasz , Martin Obergaulinger , Pablo Cerdá-Durán , Ewald Müller , Miguel-Ángel Aloy

To power gamma-ray bursts and other high-energy events, large-scale magnetic fields are required to extract rotational energy from compact objects such as black holes and neutron stars. The magnetorotational instability (MRI) is a key…

High Energy Astrophysical Phenomena · Physics 2025-09-17 Alexis Reboul-Salze , Loren E. Held , Kenta Kiuchi

The magnetorotational instability (MRI) is the leading candidate for driving turbulence, angular momentum transport, and accretion in astrophysical disks. I consider the linear theory of the MRI in a thin, equatorial disk in the Kerr…

Astrophysics · Physics 2009-11-10 Charles F. Gammie

The magnetorotational instability (MRI) is a promising mechanism to amplify the magnetic field in fast rotating protoneutron stars. The diffusion of neutrinos trapped in the PNS induces a transport of momentum, which can be modelled as a…

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

In a hot, dilute, magnetized accretion flow, the electron mean-free path can be much greater than the Larmor radius, thus thermal conduction is anisotropic and along magnetic field lines. In this case, if the temperature decreases outward,…

High Energy Astrophysical Phenomena · Physics 2015-05-20 De-Fu Bu , Feng Yuan , James M Stone

In this paper we investigate the influence of radiative transport on the growth of the magnetorotational instability (MRI) in accretion discs. The analysis is performed by use of analytical and numerical means. We provide a general…

Solar and Stellar Astrophysics · Physics 2015-05-13 M. Flaig , R. Kissmann , W. Kley

The amplification of a magnetic field due to the Richtmyer-Meshkov instability (RMI) is investigated by two-dimensional MHD simulations. Single-mode analysis is adopted to reveal definite relation between the nonlinear evolution of RMI and…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Takayoshi Sano , Katsunobu Nishihara , Chihiro Matsuoka , Tsuyoshi Inoue

The magnetorotational instability (MRI) is a fundamental process of accretion disk physics, but its saturation mechanism remains poorly understood despite considerable theoretical and computational effort. We present a multiple scales…

High Energy Astrophysical Phenomena · Physics 2017-05-24 S. E. Clark , Jeffrey S. Oishi

We present three-dimensional magnetohydrodynamic simulations of the nonlinear evolution of the magnetorotational instability (MRI) with a non-zero Ohmic resistivity. The properties of the saturated state depend on the initial magnetic field…

Astrophysics · Physics 2009-10-31 Timothy P. Fleming , James M. Stone , John F. Hawley

Magnetorotational instability (MRI) is one of the fundamental processes in astrophysics, driving angular momentum transport and mass accretion in a wide variety of cosmic objects. Despite much theoretical/numerical and experimental efforts…

Fluid Dynamics · Physics 2017-11-28 G. Mamatsashvili , F. Stefani , A. Guseva , M. Avila

The Magnetorotational Instability (MRI) has long been considered a plausibly ubiquitous mechanism to destabilize otherwise stable Keplerian flows to support radially outward transport of angular momentum. Such an efficient transport process…

Instrumentation and Methods for Astrophysics · Physics 2018-12-13 Derek M. H. Hung , Eric G. Blackman , Kyle J. Caspary , Erik P. Gilson , Hantao Ji

At second order in perturbation theory, the unstable r-mode of a rotating star includes growing differential rotation whose form and growth rate are determined by gravitational-radiation reaction. With no magnetic field, the angular…

High Energy Astrophysical Phenomena · Physics 2018-03-05 John L. Friedman , Lee Lindblom , Luciano Rezzolla , Andrey I. Chugunov

We investigate the evolution of hydromagnetic perturbations in a small section of accretion disks. It is known that molecular viscosity is negligible in accretion disks. Hence, it has been argued that a mechanism, known as Magnetorotational…

High Energy Astrophysical Phenomena · Physics 2015-08-12 Sujit Kumar Nath , Banibrata Mukhopadhyay
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