Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Limitations in the $2D$ description of the electromagnetic waves
  propagation in thin dielectric and magnetic layers
28
The categories of this paper are: alg-geom
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
18
The categories of this paper are: econ
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs
2
The categories of this paper are: math