Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Observational Constraints on Black Hole Spin
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom