title: Self-Organizing Knotted Magnetic Structures in Plasma.
abstract: We perform full-magnetohydrodynamics simulations on various initially helical configurations and show that they reconfigure into a state where the magnetic field lines span nested toroidal surfaces. This relaxed configuration is not a Taylor state, as is often assumed for relaxing plasma, but a state where the Lorentz force is balanced by the hydrostatic pressure, which is lowest on the central ring of the nested tori. Furthermore, the structure is characterized by a spatially slowly varying rotational transform, which leads to the formation of a few magnetic islands at rational surfaces. We then obtain analytic expressions that approximate the global structure of the quasistable linked and knotted plasma configurations that emerge, using maps from S^{3} to S^{2} of which the Hopf fibration is a special case. The knotted plasma configurations have a highly localized magnetic energy density and retain their structure on time scales much longer than the Alfvénic time scale.
authors.affiliation: Huygens-Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands.
authors.forename: C B
authors.initials: CB
authors.lastname: Smiet
authors.affiliation: Division of Mathematics, University of Dundee, Dundee DD1 4HN, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Candelaresi
authors.affiliation: Department of Physics, University of California Santa Barbara, Santa Barbara, California 93106, USA.
authors.forename: A
authors.initials: A
authors.lastname: Thompson
authors.affiliation: Department of Physics, University of California Santa Barbara, Santa Barbara, California 93106, USA.
authors.forename: J
authors.initials: J
authors.lastname: Swearngin
authors.affiliation: Huygens-Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands.
authors.forename: J W
authors.initials: JW
authors.lastname: Dalhuisen
authors.affiliation: Huygens-Kamerlingh Onnes Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands.|Department of Physics, University of California Santa Barbara, Santa Barbara, California 93106, USA.
authors.forename: D
authors.initials: D
authors.lastname: Bouwmeester