Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Infrared nano-spectroscopy of ferroelastic domain walls in hybrid
  improper ferroelectric Ca$_3$Ti$_2$O$_7$
36
The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
13
The categories of this paper are: quant-ph