Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Investigation of geometry-dependent field properties of 3D printed
  metallic photonic crystals
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
6
The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
30
The categories of this paper are: q-alg
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
7
The categories of this paper are: hep-th