Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The generalised continuous algebraic Riccati equation and impulse-free
  continuous-time LQ optimal control
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
37
The categories of this paper are: supr-con
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
28
The categories of this paper are: alg-geom
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
1
The categories of this paper are: cs
16
The categories of this paper are: stat
26
The categories of this paper are: bayes-an
6
The categories of this paper are: astro-ph