Related papers: Quasi-two-dimensionality of three-dimensional, mag…
We present new simulations of decaying hydromagnetic turbulence for a relativistic equation of state relevant to the early universe. We compare helical and nonhelical cases either with kinetically or magnetically dominated initial fields.…
Decaying three-dimensional (3D) turbulence is studied via direct numerical simulations (DNS) for an isotropic non-rotating flow and for rotating flows with and without helicity. We analyze the cases of moderate Rossby number and large…
Compressible magnetohydrodynamic (MHD) turbulence is ubiquitous in astrophysical phenomena ranging from the intergalactic to the stellar scales. In studying them, numerical simulations are nearly inescapable, due to the large degree of…
We present a two-fluid magnetohydrodynamics (MHD) model of quasi-stationary, two-dimensional magnetic reconnection in an incompressible plasma composed of electrons and ions. We find two distinct regimes of slow and fast reconnection. The…
A weak wave turbulence theory is developed for two-dimensional (2D) magnetohydrodynamics (MHD). We derive and analyze the kinetic equation describing the three-wave interactions of pseudo-Alfv\'en waves. Our analysis is greatly helped by…
The extent to which large scale magnetic fields are susceptible to turbulent diffusion is important for interpreting the need for in situ large scale dynamos in astrophysics and for observationally inferring field strengths compared to…
Recent progress regarding the noncanonical Hamiltonian formulation of extended magnetohydrodynamics (XMHD), a model with Hall drift and electron inertia, is summarized. The advantages of the Hamiltonian approach are invoked to study some…
Through a direct comparison between numerical simulations in two and three dimensions, we investigate topological effects in reconnection. A simple estimate on increase in reconnection rate in three dimensions by a factor of $\sqrt{2}$,…
Magnetic field embedded in a perfectly conducting fluid preserves its topology for all time. Although ionized astrophysical objects, like stars and galactic disks, are almost perfectly conducting, they show indications of changes in…
We present an exact analytic solution for decaying incompressible magnetohydrodynamic (MHD) turbulence. Our solution reveals a dual formulation in terms of two interacting Euler ensembles--one for hydrodynamic and another for magnetic…
We investigate long-time properties of three-dimensional MHD turbulence in the absence of forcing and examine in particular the role played by the quadratic invariants of the system and by the symmetries of the initial configurations. We…
We present numerical studies of 3-dimensional magnetohydrodynamic (MHD) turbulence in a strongly magnetized medium in the extremely relativistic limit, in which the inertia of the charge carriers can be neglected. We have focused on strong…
In an inhomogeneous magnetised plasma the transport of energy and particles perpendicular to the magnetic field is in general mainly caused by quasi two-dimensional turbulent fluid mixing. The physics of turbulence and structure formation…
One of the most important predictions in magnetohydrodynamics (MHD) is that in the presence of a uniform magnetic field $\textbf{b}_{0}$ a transition from weak to strong wave turbulence should occur when going from large to small…
The relevance of two-dimensional three-components (2D3C) flows goes well beyond their occurrence in nature, and a deeper understanding of their dynamics might be also helpful in order to shed further light on the dynamics of pure…
A systematic procedure to derive shell models for MHD turbulence is proposed. It takes into account the conservation of ideal quadratic invariants such as the total energy, the cross-helicity and the magnetic helicity as well as the…
Magnetic reconnection is a fundamental process in a laboratory, magnetospheric, solar and astrophysical plasma, whereby magnetic energy is converted into heat, bulk kinetic energy and fast particle energy. Its nature in two dimensions is…
Realistic astrophysical environments are turbulent due to the extremely high Reynolds numbers. Therefore, the theories of reconnection intended for describing astrophysical reconnection should not ignore the effects of turbulence on…
Scale interactions in Hall MHD are studied using both the mean field theory derivation of transport coefficients, and direct numerical simulations in three space dimensions. In the magnetically dominated regime, the eddy resistivity is…
Magnetized turbulence is ubiquitous in many astrophysical and terrestrial systems but no complete, uncontested theory even in the simplest form, magnetohydrodynamics (MHD), exists. Many theories and phenomenologies focus on the joint…