Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Ricci Nilsoliton Black Holes
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
20
The categories of this paper are: acc-phys
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics