Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Opening up and control of spectral gaps of the Laplacian in periodic
  domains
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
0
The categories of this paper are: hep-ph
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
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
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex