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arXiv 2103.00617math.DGmath.ATmath.KT
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$\mathbf{Pin}^\pm$- 与 $\mathbf{Spin}^c$-流形上的正标量曲率

Positive scalar curvature on $\mathbf{Pin}^\pm$- and $\mathbf{Spin}^c$-manifolds

Boris Botvinnik, Jonathan Rosenberg

AI总结:

本文研究具有spin$^c$或pin$^\pm$结构的非旋量流形,证明狄拉克算子指标完全控制特殊子流形附近不变psc-度量的存在性,并将流形对解释为带纤维化奇点的流形。

摘要:

众所周知,旋量结构和狄拉克算子在紧致流形上正标量曲率度量(psc-度量)的研究中起着关键作用。这里我们考虑一类具有“几乎旋量”结构的非旋量流形,即具有spin$^c$或pin$^\pm$结构的流形。结果表明,在这些情形下(在对此类流形$M$的自然假设下),相关狄拉克算子的指标完全控制了在$M$的“特殊子流形”$B$附近具有$S^1$-或$C_2$-不变性的psc-度量的存在性。该子流形$B\subset M$与决定$M$上spin$^c$或pin$^\pm$结构的复(分别为实)线丛$L$对偶。我们还表明,这些流形对$(M,B)$可以被解释为配备“良好适配的psc-度量”的“具有纤维化奇点的流形”。本综述基于我们近期的研究以及我们与Paolo Piazza的合作工作。

英文摘要:

It is well-known that spin structures and Dirac operators play a crucial role in the study of positive scalar curvature metrics (psc-metrics) on compact manifolds. Here we consider a class of non-spin manifolds with "almost spin" structure, namely those with spin$^c$ or pin$^\pm$-structures. It turns out that in those cases (under natural assumptions on such a manifold $M$), the index of a relevant Dirac operator completely controls existence of a psc-metric which is $S^1$- or $C_2$-invariant near a "special submanifold" $B$ of $M$. This submanifold $B\subset M$ is dual to the complex (respectively, real) line bundle $L$ which determines the spin$^c$ or pin$^\pm$ structure on $M$. We also show that these manifold pairs $(M,B)$ can be interpreted as "manifolds with fibered singularities" equipped with "well-adapted psc-metrics". This survey is based on our recent work as well as on our joint work with Paolo Piazza.

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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