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arXiv 2410.02461math.GT
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两个同调环面连通和的Dehn扭转

The Dehn twist on a connected sum of two homology tori

Haochen Qiu

AI总结:

本文推广Pin(2)-等变族Bauer-Furuta不变量至非单连通流形,并构造精细化,证明两个同调环面连通和颈部沿3-球面的Dehn扭转非光滑同伦于恒同,条件为行列式均为奇数。

摘要:

Kronheimer-Mrowka证明了在两个K3曲面颈部沿3-球面的Dehn扭转不与恒同映射光滑同伦。他们的结果要求流形是单连通的,且其中一个流形的符号差为16 mod 32。我们将Pin(2)-等变族Bauer-Furuta不变量推广到非单连通流形,并构造了该不变量的一个精细化。我们利用它证明,若X1,X2是两个同调环面,且它们的行列式r1,r2均为奇数,则沿X1#X2颈部3-球面的Dehn扭转不与恒同映射光滑同伦。

英文摘要:

Kronheimer-Mrowka shows that the Dehn twist along a $3$-sphere in the neck of two $K3$ surfaces is not smoothly isotopic to the identity. Their result requires that the manifolds are simply connected and the signature of one of them is $16 \mod 32$. We generalize the Pin$(2)$-equivariant family Bauer-Furuta invariant to nonsimply connected manifolds, and construct a refinement of this invariant. We use it to show that, if $X_1,X_2$ are two homology tori such that the determinants $r_1,r_2$ of them are odd, then the Dehn twist along a $3$-sphere in the neck of $X_1\# X_2$ is not smoothly isotopic to the identity.

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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