Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nef and semiample divisors on rational surfaces   In this paper we study smooth projective rational surfaces, defined over an
algebraically closed field of any characteristic, with pseudo-effective
anticanonical divisor. We provide a necessary and sufficient condition in order
for any nef divisor to be semiample. We adopt our criterion to investigate Mori
dream surfaces in the complex case.

7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
25
The categories of this paper are: patt-sol
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph