Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Universal torsors of Del Pezzo surfaces and homogeneous spaces   Let Cox(S) be the homogeneous coordinate ring of the blow-up S of P^2 in r
general points, i.e., a smooth Del Pezzo surface of degree 9-r. We prove that
for r=6 and 7, Proj(Cox(S)) can be embedded into G/P, where G is an algebraic
group with root system given by the primitive Picard lattice of S and P is a
certain maximal parabolic subgroup in G.

23
The categories of this paper are: solv-int
26
The categories of this paper are: bayes-an
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
11
The categories of this paper are: hep-lat