Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Coherent perfect absorbers for transient, periodic or chaotic optical
  fields: time-reversed lasers beyond threshold
35
The categories of this paper are: mtrl-th
23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
18
The categories of this paper are: econ
1
The categories of this paper are: cs
2
The categories of this paper are: math
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci