English

A note on K$\ddot{a}$hler manifolds with almost nonnegative bisectional curvature

Differential Geometry 2008-11-10 v2

Abstract

In this note we prove the following result: There is a positive constant ϵ(n,Λ)\epsilon(n,\Lambda) such that if MnM^n is a simply connected compact Ka¨\ddot{a}hler manifold with sectional curvature bounded from above by Λ\Lambda, diameter bounded from above by 1, and with holomorphic bisectional curvature Hϵ(n,Λ)H \geq -\epsilon(n,\Lambda), then MnM^n is diffeomorphic to the product M1×...×MkM_1\times ... \times M_k, where each MiM_i is either a complex projective space or an irreducible Ka¨\ddot{a}hler-Hermitian symmetric space of rank 2\geq 2. This resolves a conjecture of F. Fang under the additional upper bound restrictions on sectional curvature and diameter.

Keywords

Cite

@article{arxiv.0807.2310,
  title  = {A note on K$\ddot{a}$hler manifolds with almost nonnegative bisectional curvature},
  author = {Hong Huang},
  journal= {arXiv preprint arXiv:0807.2310},
  year   = {2008}
}

Comments

3 pages, some corrections

R2 v1 2026-06-21T11:00:34.232Z