28 research outputs found
On the curvature of Einstein-Hermitian surfaces
We give a mathematical exposition of the Page metric, and introduce an
efficient coordinate system for it. We carefully examine the submanifolds of
the underlying smooth manifold, and show that the Page metric does not have
positive holomorphic bisectional curvature. We exhibit a holomorphic subsurface
with flat normal bundle. We also give another proof of the fact that a compact
complex surface together with an Einstein-Hermitian metric of positive
orthogonal bisectional curvature is biholomorphically isometric to the complex
projective plane with its Fubini-Study metric up to rescaling. This result
relaxes the K\"ahler condition in Berger's theorem, and the positivity
condition on sectional curvature in a theorem proved by the second author.Comment: 16 pages, Page metric coefficient and Vierbein are fixed, Journal
info added. arXiv admin note: text overlap with arXiv:1112.418
Conformally K\"ahler surfaces and orthogonal holomorphic bisectional curvature
We show that a compact complex surface which admits a conformally K\"ahler
metric g of positive orthogonal holomorphic bisectional curvature is
biholomorphic to the complex projective plane. In addition, if g is a Hermitian
metric which is Einstein, then the biholomorphism can be chosen to be an
isometry via which g becomes a multiple of the Fubini-Study metric.Comment: 12 pages. Journal information adde