arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2302.10091math.DGmath.MG
收藏

非负曲率Alexandrov空间上的等周问题与无穷远结构

Isoperimetric problem and structure at infinity on Alexandrov spaces with nonnegative curvature

Gioacchino Antonelli, Marco Pozzetta

AI总结:

研究非负曲率有限维Alexandrov空间的等周剖面、等周集存在性与无穷远渐近结构的关系,证明线性体积增长等条件的等价性,并给出2维情形下等周集的存在性与拓扑刻画。

摘要:

本文研究具有非坍缩条件(即单位球的体积具有一致下界)的非负曲率有限维Alexandrov空间。我们研究此类空间的等周剖面、等周集的存在性与无穷远渐近结构之间的关系。在此设定下,我们证明以下条件等价:空间具有线性体积增长;在无穷远处Gromov--Hausdorff渐近于一个柱面;具有一致有界的等周剖面;整个空间是某条直线或射线的管状邻域。此外,在满足上述任一条件的空间上,我们证明了对于足够大的体积存在等周集,并刻画了等周剖面层面的几何刚性。将研究专门限于2维情形,我们证明单位球的体积始终具有一致下界,证明了对于任意体积均存在等周集,并在空间无边界时刻画了其拓扑。证明采用变分方法,特别适用于具有非负截面曲率的Riemannian流形和Euclid凸体。据作者所知,多数结果在这些光滑情形下也是新的。

英文摘要:

In this paper we consider nonnegatively curved finite dimensional Alexandrov spaces with a non-collapsing condition, i.e., such that unit balls have volumes uniformly bounded from below away from zero. We study the relation between the isoperimetric profile, the existence of isoperimetric sets, and the asymptotic structure at infinity of such spaces. In this setting, we prove that the following conditions are equivalent: the space has linear volume growth; it is Gromov--Hausdorff asymptotic to one cylinder at infinity; it has uniformly bounded isoperimetric profile; the entire space is a tubular neighborhood of either a line or a ray. Moreover, on a space satisfying any of the previous conditions, we prove existence of isoperimetric sets for sufficiently large volumes, and we characterize the geometric rigidity at the level of the isoperimetric profile. Specializing our study to the $2$-dimensional case, we prove that unit balls have always volumes uniformly bounded from below away from zero, and we prove existence of isoperimetric sets for every volume, characterizing also their topology when the space has no boundary. The proofs exploit a variational approach, and in particular apply to Riemannian manifolds with nonnegative sectional curvature and to Euclidean convex bodies. Up to the authors' knowledge, most of the results are new even in these smooth cases.

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。

↑