Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Comment on ''Photonic Band Gaps: Noncommuting limit and the 'Acoustic
  Band'''   This comment concerns the homogenization of 2D dielectric photonic crystals,
and the fact that the limits $k\to 0$ ($k$ is the Bloch vector) and $\epsilon
\to +\infty $ do not commute for $p$-polarized waves

11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat