2026-06-27T15:46:00Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/589742023-08-04T02:17:55Zcom_20.500.14352_14col_20.500.14352_15

Fernández-Rañada, Antonio 2023-06-20T18:56:46Z 2023-06-20T18:56:46Z 2000-11 1063-651X 10.1103/PhysRevE.62.7181 https://hdl.handle.net/20.500.14352/58974 http://dx.doi.org/10.1103/PhysRevE.62.7181 http://journals.aps.org The stability of fireballs in a recent model of ball lightning is studied. It is shown that the balls shine while relaxing in:in almost quiescent expansion, and that three effects contribute to their stability: (i) the formation in each one during a process of Taylor relaxation of a force-free magnetic field, a concept introduced in 1954 in order to explain the existence of large magnetic fields and currents in stable configurations of astrophysical plas,nas; (ii) the so called Alfven conditions in magnetohydrodynamics; and (iii) the approximate conservation of the helicity integral. The force-free fields that appear are termed "knots" because their magnetic lines are closed and linked. eng open access Ball lightning as a force-free magnetic knot journal article