Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Fano Manifolds, Contact Structures, and Quaternionic Geometry   Let Z be a compact complex (2n+1)-manifold which carries a {\em complex
contact structure}, meaning a codimension-1 holomorphic sub-bundle D of TZ
which is maximally non-integrable. If Z admits a K\"ahler-Einstein metric of
positive scalar curvature, we show that it is the Salamon twistor space of a
quaternion-K\"ahler manifold (M^{4n}, g). If Z also admits a second complex
contact structure, then Z= CP_{2n+1}. As an application, we give several new
characterizations of the Riemannian manifold HP_n=Sp(n+1)/( Sp(n)\times Sp(1)).

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The categories of this paper are: comp-gas
20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol
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The categories of this paper are: alg-geom
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The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
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The categories of this paper are: atom-ph
9
The categories of this paper are: nlin
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The categories of this paper are: math-ph