Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Engineering of multi-dimensional entangled states of photon pairs using
  hyper-entanglement
30
The categories of this paper are: q-alg
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an