Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Direct Wide-angle Measurement of Photonic Band- structure in a
  Three-dimensional Photonic Crystal using Infrared Fourier Imaging
  Spectroscopy
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
21
The categories of this paper are: adap-org
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
23
The categories of this paper are: solv-int
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
26
The categories of this paper are: bayes-an