Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Radiation of caustic beams from a collapsing bullet   Collapse of an intense (2+1)-dimensional wave packet in a medium with cubic
nonlinearity and a two-dimensional dispersion of an order higher than parabolic
is studied both theoretically and experimentally. The carrier waves are
microwave backward volume spin waves which propagate in a stripe made from a
thin ferrimagnetic film and the packet is a spin-wave bullet. We show that
before being self-destroyed the bullet irradiates untrapped dispersive waves,
which is in agreement with a previous theoretical prediction. Since, in
addition, the ferromagnetic medium is characterized by an induced uniaxial
anisotropy, this radiation takes the form of narrow beams of continuous waves
at very specific angles to its propagation direction. Based on our theoretical
calculations we find that these beams are caustic beams and the angles are the
characteristic spin-wave caustic angles modified by the motion of the source.

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The categories of this paper are: dg-ga
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The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
10
The categories of this paper are: q-bio
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
5
The categories of this paper are: gr-qc