Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On birational involutions of $P^3$   Let $X$ be a rationally connected three-dimensional algebraic variety and let
$\tau$ be an element of order two in the group of its birational selfmaps.
Suppose that there exists a non-uniruled divisorial component of the
$\tau$-fixed point locus. Using the equivariant minimal model program we give a
rough classification of such elements.

11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat