Ricci curvature bounds and rigidity for non-smooth Riemannian and semi-Riemannian metrics

التفاصيل البيبلوغرافية
العنوان: Ricci curvature bounds and rigidity for non-smooth Riemannian and semi-Riemannian metrics
المؤلفون: Kunzinger, Michael, Ohanyan, Argam, Vardabasso, Alessio
سنة النشر: 2024
المجموعة: Mathematics
مصطلحات موضوعية: Mathematics - Differential Geometry, Mathematics - Metric Geometry, 53C21, 53C24, 46T30, 49Q22
الوصف: We study rigidity problems for Riemannian and semi-Riemannian manifolds with metrics of low regularity. Specifically, we prove a version of the Cheeger-Gromoll splitting theorem \cite{CheegerGromoll72splitting} for Riemannian metrics and the flatness criterion for semi-Riemannian metrics of regularity $C^1$. With our proof of the splitting theorem, we are able to obtain an isometry of higher regularity than the Lipschitz regularity guaranteed by the $\mathsf{RCD}$-splitting theorem \cite{gigli2013splitting, gigli2014splitoverview}. Along the way, we establish a Bochner-Weitzenb\"ock identity which permits both the non-smoothness of the metric and of the vector fields, complementing a recent similar result in \cite{mondino2024equivalence}. The last section of the article is dedicated to the discussion of various notions of Sobolev spaces in low regularity, as well as an alternative proof of the equivalence (see \cite{mondino2024equivalence}) between distributional Ricci curvature bounds and $\mathsf{RCD}$-type bounds, using in part the stability of the variable $\mathsf{CD}$-condition under suitable limits \cite{ketterer2017variableCD}.
Comment: 37 pages
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2406.06762
رقم الأكسشن: edsarx.2406.06762
قاعدة البيانات: arXiv