title: Large-scale dynamics of magnetic helicity.
abstract: In this paper we investigate the dynamics of magnetic helicity in magnetohydrodynamic (MHD) turbulent flows focusing at scales larger than the forcing scale. Our results show a nonlocal inverse cascade of magnetic helicity, which occurs directly from the forcing scale into the largest scales of the magnetic field. We also observe that no magnetic helicity and no energy is transferred to an intermediate range of scales sufficiently smaller than the container size and larger than the forcing scale. Thus, the statistical properties of this range of scales, which increases with scale separation, is shown to be described to a large extent by the zero flux solutions of the absolute statistical equilibrium theory exhibited by the truncated ideal MHD equations.
authors.affiliation: Department of Physics and INFN, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy.|SUPA, School of Physics and Astronomy, University of Edinburgh, Peter Guthrie Tait Road, EH9 3FD, United Kingdom.
authors.forename: Moritz
authors.initials: M
authors.lastname: Linkmann
authors.affiliation: Department of Applied Mathematics, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Vassilios
authors.initials: V
authors.lastname: Dallas