title: Radiation of caustic beams from a collapsing bullet.
abstract: We show both theoretically and experimentally that a collapsing (2+1)-dimensional wave packet in a medium with cubic nonlinearity and a two-dimensional dispersion of an order higher than parabolic irradiates untrapped dispersive waves. The studies are performed for a spin-wave bullet propagating in an in-plane magnetized ferrimagnetic film. An induced uniaxial anisotropy in such a medium leads to the formation of narrow spin-wave caustic beams whose angles to the bullet's propagation direction are modified by the motion of the source.
authors.affiliation: School of Physics, M013, University of Western Australia, Crawley, WA 6009, Australia.
authors.forename: M P
authors.initials: MP
authors.lastname: Kostylev
authors.forename: A A
authors.initials: AA
authors.lastname: Serga
authors.forename: B
authors.initials: B
authors.lastname: Hillebrands