title: Dissipative dynamics of superfluid vortices at nonzero temperatures.
abstract: We consider the evolution and dissipation of vortex rings in a condensate at nonzero temperatures in the context of the classical field approximation, based on the defocusing nonlinear Schrödinger equation. The temperature in such a system is fully determined by the total number density and the number density of the condensate. The collisions with noncondensed particles reduce the radius of a vortex ring until it completely disappears. We obtain a universal decay law for a vortex line length and relate it to mutual friction coefficients in the fundamental equation of vortex motion in superfluids.
authors.affiliation: Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, UK.
authors.forename: Natalia G
authors.initials: NG
authors.lastname: Berloff
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Youd