Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Geometrical Optical Illusion via Sub-Riemannian Geodesics in the
  Roto-Translation Group
18
The categories of this paper are: econ
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
23
The categories of this paper are: solv-int
13
The categories of this paper are: quant-ph
36
The categories of this paper are: cmp-lg
30
The categories of this paper are: q-alg
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol