Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Topological defects, pattern evolution, and hysteresis in thin magnetic
  films   Nature of the magnetic hysteresis for thin films is studied by the
Monte-Carlo simulations. It is shown that a reconstruction of the magnetization
pattern with external field occurs via the creation of vortex-antivortex pairs
of a special kind at the boundaries of stripe domains. It is demonstrated that
the symmetry of order parameter is of primary importance for this problem, in
particular, the in-plane magnetic anisotropy is necessary for the hysteresis.

23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc