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arXiv 2205.00543math.DG
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四维数量曲率的极值性与刚性

Extremality and rigidity for scalar curvature in dimension four

Renato G. Bettiol, McFeely Jackson Goodman

AI总结:

本文研究四维 Riemann 流形数量曲率的面积极值与刚性,借助扭曲 Dirac 算子及 Finsler–Thorpe 技巧证明非负截面曲率紧 4-流形和正曲率区域的相应极值性。

摘要:

遵循 Gromov 的定义,若一个 Riemann 流形的任何会增大数量曲率的修改都必然减小某个切 2-平面的面积,则称其为面积极值的。我们证明,具有非负截面曲率的一大类紧 4-流形(无论是否带边)都是面积极值的。我们还表明,4-流形上所有正截面曲率区域均局部面积极值。这些结果通过分析由成对度量构造的扭曲 Dirac 算子核中的截面,并利用 Finsler–Thorpe 技巧处理四维截面曲率界而得到。

英文摘要:

Following Gromov, a Riemannian manifold is called area-extremal if any modification that increases scalar curvature must decrease the area of some tangent 2-plane. We prove that large classes of compact 4-manifolds, with or without boundary, with nonnegative sectional curvature are area-extremal. We also show that all regions of positive sectional curvature on 4-manifolds are locally area-extremal. These results are obtained analyzing sections in the kernel of a twisted Dirac operator constructed from pairs of metrics, and using the Finsler--Thorpe trick for sectional curvature bounds in dimension 4.

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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