20 citations · 133 across the 24 of their papers we have counts for
24 papers
Magnetic Dynamo Driven by Inertial Waves
A. Mishra, G. Mamatsashvili, M. Le Bars +2
We demonstrate, by studying precession-driven flows, that inertial wave hydrodynamic turbulence can drive a robust magnetic dynamo action. Motivated by the stronger damping of larg…
Leveling of MHD turbulence imbalance in shear flows
M. Kavtaradze, G. Mamatsashvili, G. Chagelishvili +1
We investigate magnetohydrodynamic (MHD) turbulence in plane shear flows with a streamwise background magnetic field in the super-Alfvénic regime, i.e., when the flow velocity is l…
Tidal triggers and the predictability of solar activity
F. Stefani, G. M. Horstmann, G. Mamatsashvili +1
Magneto-Rossby waves in the solar tachocline are currently considered to be one of the main determinants of solar activity. In particular, they can give rise to the quasi-biennial…
Reappraising the Elatina series: What if the Solar Interpretation Were Correct?
F. Stefani, M. Gugliotta, G. M. Horstmann +2
We revisit the sedimentary laminae from the Neoproterozoic Elatina Formation of South Australia. These were first interpreted as varves driven by solar activity and later as tidali…
Adding further pieces to the synchronization puzzle: QBO, bimodality, and phase jumps
F. Stefani, G. M. Horstmann, G. Mamatsashvili +1
This work builds on a recently developed self-consistent synchronization model of the solar dynamo which attempts to explain Rieger-type periods, the Schwabe/Hale cycle and the Sue…
The effect of split endcaps on the flow dynamics in a tall Taylor-Couette setup
A. Mishra, P. Personnettaz, G. Mamatsashvili +2
The effects of axial boundaries, or endcaps are of fundamental interest in many Taylor-Couette (TC) flow experiments. A main challenge in those experiments has been to minimize the…
Strong and weak dynamo regimes in Taylor-Couette flows
A. Mishra, G. Mamatsashvili, F. Stefani
We reveal a nonlinear magnetic dynamo in a Taylor-Couette flow at small magnetic Prandtl numbers , which has been previously believed to exist only at higher $Pm\gtrsim 1…
One-winged butterflies: mode selection for azimuthal magnetorotational instability by thermal convection
A. Mishra, G. Mamatsashvili, M. Seilmayer +1
The effects of thermal convection on turbulence in accretion discs, and particularly its interplay with the magnetorotational instability (MRI), are of significant astrophysical in…
Dynamo action driven by precessional turbulence
V. Kumar, F. Pizzi, G. Mamatsashvili +3
We reveal and analyze an efficient magnetic dynamo action due to precession-driven hydrodynamic turbulence in the local model of a precessional flow, focusing on the kinematic stag…
MRI turbulence in vertically stratified accretion discs at large magnetic Prandtl numbers
Loren E. Held, George Mamatsashvili, Martin E. Pessah
The discovery of the first binary neutron star merger, GW170817, has spawned a plethora of global numerical relativity simulations. These simulations are often ideal (with dissipat…
Rieger, Schwabe, Suess-de Vries: The Sunny Beats of Resonance
F. Stefani, G. M. Horstmann, M. Klevs +2
We propose a self-consistent explanation of Rieger-type periodicities, the Schwabe cycle, and the Suess-de Vries cycle of the solar dynamo in terms of resonances of various wave ph…
Non-axisymmetric modes of magnetorotational and possible hydrodynamical instabilities in the upcoming DRESDYN-MRI experiments -- linear and nonlinear dynamics
A. Mishra, G. Mamatsashvili, F. Stefani
The quest for an unambiguous detection of magnetorotational instability (MRI) in experiments is still ongoing despite recent promising results. To conclusively identify MRI in the…
Alfvén wave experiments with liquid rubidium in a pulsed magnetic field
Th. Gundrum, J. Forbriger, Th. Herrmannsdörfer +4
Magnetic fields are key ingredients for heating the solar corona to temperatures of several million Kelvin. A particularly important region with respect to this is the so-called ma…
Nonlinear evolution of magnetorotational instability in a magnetized Taylor-Couette flow: scaling properties and relation to upcoming DRESDYN-MRI experiment
A. Mishra, G. Mamatsashvili, F. Stefani
Magnetorotational instability (MRI) is the most likely mechanism driving angular momentum transport in astrophysical disks. However, despite many efforts, a conclusive experimental…
Interplay between geostrophic vortices and inertial waves in precession-driven turbulence
F. Pizzi, G. Mamatsashvili, A. J. Barker +2
The properties of rotating turbulence driven by precession are studied using direct numerical simulations and analysis of the underlying dynamical processes in Fourier space. The s…
Tidally Forced Planetary Waves in the Tachocline of Solar-like Stars
G. M. Horstmann, G. Mamatsashvili, A. Giesecke +2
Can atmospheric waves in planet-hosting solar-like stars substantially resonate to tidal forcing? Substantially at a level of impacting the space weather or even of being dynamo-re…
MRI turbulence in accretion discs at large magnetic Prandtl numbers
Loren E. Held, George Mamatsashvili
The effect of large magnetic Prandtl number (the ratio of viscosity to resistivity) on the turbulent transport and energetics of the magnetorotational instability (MRI)…
From helical to standard magnetorotational instability: predictions for upcoming liquid sodium experiments
A. Mishra, G. Mamatsashvili, F. Stefani
We conduct a linear analysis of axisymmetric magnetorotational instability (MRI) in a magnetized cylindrical Taylor-Couette (TC) flow for its standard version (SMRI) with a purely…
Convective, absolute and global azimuthal magnetorotational instabilities
A. Mishra, G. Mamatsashvili, V. Galindo +1
We study the convective and absolute forms of azimuthal magnetorotational instability (AMRI) in a Taylor-Couette (TC) flow with an imposed azimuthal magnetic field. We show that th…
Zero net flux MRI-turbulence in disks sustenance scheme and magnetic Prandtl number dependence
George Mamatsashvili, George Chagelishvili, Martin E. Pessah +2
We investigate sustenance and dependence on magnetic Prandtl number () for magnetorotational instability (MRI)-driven turbulence in astrophysical Keplerian disks with zer…
Quasi-two-dimensional nonlinear evolution of helical magnetorotational instability in a magnetized Taylor-Couette flow
G. Mamatsashvili, F. Stefani, A. Guseva +1
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.…
Nonlinear transverse cascade and sustenance of MRI-turbulence in Keplerian disks with an azimuthal magnetic field
D. Gogichaishvili, G. Mamatsashvili, W. Horton +2
We investigate magnetohydrodynamic turbulence driven by the magnetorotational instability (MRI) in Keplerian disks with a nonzero net azimuthal magnetic field using shearing box si…
Magnetic field dynamos and magnetically triggered flow instabilities
Frank Stefani, Thomas Albrecht, Rainer Arlt +13
The project A2 of the LIMTECH Alliance aimed at a better understanding of those magnetohydrodynamic instabilities that are relevant for the generation and the action of cosmic magn…
Linking dissipation-induced instabilities with nonmodal growth: the case of helical magnetorotational instability
George Mamatsashvili, Frank Stefani
The helical magnetorotational instability is known to work for resistive rotational flows with comparably steep negative or extremely steep positive shear. The corresponding lower…