Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Einstein Hermitian Metrics of Non Negative Sectional Curvature   We prove that a simpy connected Hermitian Einstein 4-manifold with
non-negative sectional curvature is isometric to complex projective space
$\mathbb{C}\mathbb{P}^{2}$ with the Fubini-Study metric or isometric to the
product $\mathbb{S}^{2}\times \mathbb{S}^{2}$ with the canonical metric.

4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
6
The categories of this paper are: astro-ph
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph