Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Extended Klein model and a bound on curves with negative
  self-intersection   Let $S$ be an irreducible smooth projective surface and $\mathcal{F}$ a
collection of curves with negative self-intersection on $S$ such that no
positive combination $aC_1 + bC_2$ is connected nef. In this paper, we provide
an alternate proof that $\mathcal{F}$ is bounded by an exponential function of
the Picard number $\rho(S)$ of $S$ using an extended version of the Klein disc
model for hyperbolic space.

26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
22
The categories of this paper are: chao-dyn
29
The categories of this paper are: funct-an