English

Connected sums of almost complex manifolds

Differential Geometry 2018-08-27 v2 Algebraic Topology Geometric Topology Symplectic Geometry

Abstract

In this paper, firstly, for some 4n4n-dimensional almost complex manifolds Mi, 1iαM_{i}, ~1\le i \le \alpha, we prove that (i=1αMi)(α1)CP2n\left(\sharp_{i=1}^{\alpha} M_{i}\right) \sharp (\alpha{-}1) \mathbb{C} P^{2n} must admits an almost complex structure, where α\alpha is a positive integer. Secondly, for a 2n2n-dimensional almost complex manifold MM, we get that MCPnM\sharp \overline{\mathbb{C} P^{n}} also admits an almost complex structure. At last, as an application, we obtain that αCP2nβCP2n\alpha\mathbb{C} P^{2n}\sharp \beta\overline{\mathbb{C} P^{2n}} admits an almost complex structure if and only if α\alpha is odd.

Keywords

Cite

@article{arxiv.1808.07343,
  title  = {Connected sums of almost complex manifolds},
  author = {Huijun Yang},
  journal= {arXiv preprint arXiv:1808.07343},
  year   = {2018}
}
R2 v1 2026-06-23T03:40:43.840Z