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arXiv 1809.06150math.DG
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正曲率四维流形

Four-manifolds with positive curvature

R. Diógenes, E. Ribeiro, E. Rufino

摘要:

本文证明了四维紧致定向半共形平坦黎曼流形$M^4$是拓扑$\mathbb{S}^{4}$或$\mathbb{C}\mathbb{P}^{2},$,只要截面曲率都在区间$[\frac{3\sqrt{3}-5}{4},\,1].$内。我们用双正交的概念(截面)曲率,以获得一个捏条件,保证一个四-维紧致流形同胚于复射影平面或$4$-球面的连通和。

英文摘要:

In this note we prove that a four-dimensional compact oriented half-confor\-mally flat Riemannian manifold $M^4$ is topologically $\mathbb{S}^{4}$ or $\mathbb{C}\mathbb{P}^{2},$ provided that the sectional curvatures all lie in the interval $[\frac{3\sqrt{3}-5}{4},\,1].$ In addition, we use the notion of biorthogonal (sectional) curvature to obtain a pinching condition which guarantees that a four-dimensional compact manifold is homeomorphic to a connected sum of copies of the complex projective plane or the $4$-sphere.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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