Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Reaction-diffusion front crossing a local defect   The interaction of a Zeldovich reaction-diffusion front with a localized
defect is studied numerically and analytically. For the analysis, we start from
conservation laws and develop simple collective variable ordinary differential
equations for the front position and width. Their solutions are in good
agreement with the solutions of the full problem. Finally using this reduced
model, we explain the pinning of the front on a large defect and obtain a
quantitative criterion.

3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg