Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Variational speed selection for the interface propagation in
  superconductors   We study the interface propagation in superconductors by means of a
variational method. We compute the lower and upper bounds for which the planar
front speed propagation is valid. To take into account delay or memory effects
in the front propagation, an hyperbolic differential equation is introduced as
an extension of the model.

24
The categories of this paper are: dg-ga
10
The categories of this paper are: q-bio
23
The categories of this paper are: solv-int
30
The categories of this paper are: q-alg
32
The categories of this paper are: atom-ph
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
26
The categories of this paper are: bayes-an
2
The categories of this paper are: math
1
The categories of this paper are: cs
9
The categories of this paper are: nlin