Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The frozen-field approximation and the Ginzburg-Landau equations of
  superconductivity   The Ginzburg--Landau (GL) equations of superconductivity provide a
computational model for the study of magnetic flux vortices in type-II
superconductors. In this article we show through numerical examples and
rigorous mathematical analysis that the GL model reduces to the frozen-field
model when the charge of the Cooper pairs (the superconducting charge carriers)
goes to zero while the applied field stays near the upper critical field.

25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
4
The categories of this paper are: cond-mat
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
15
The categories of this paper are: nucl-ex
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int