Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: 8 x 8 Terahertz Photoconductive Antenna Array and Parallelized Signal
  Acquisition System for Fast Spatially Resolved Time Domain Spectroscopy
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
9
The categories of this paper are: nlin
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
16
The categories of this paper are: stat
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph