Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: A HJB-POD approach for the control of nonlinear PDEs on a tree structure
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
4
The categories of this paper are: cond-mat
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
3
The categories of this paper are: physics
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an