Integrals and Rigidity on Manifolds with Nonnegative Ricci Curvature
Zixuan Chen, Guoyi Xu, Shuai Zhang
TL;DR
The paper addresses sharp mean value control on manifolds with nonnegative Ricci curvature, removing the radius limitation of Schoen–Yau and linking mean value equality to Euclidean rigidity. It introduces a weighted framework via the Green function, proves a radius-free sharp mean value inequality and its rigidity, and develops a detailed asymptotic study of level-set geometry for the Green-function-derived height function $b$. A central achievement is an explicit scale-invariant formula for the weighted integral of scalar curvature in dimension three, $\lim_{r\to\infty} \frac{\int_{b\le r} R\cdot |\nabla b|}{r}=8\pi[1-\mathrm{V}_M]$, which yields an alternative proof of Hamilton’s pinching conjecture in this setting. The results hinge on new tools: a generalized divergence theorem for geodesic balls, a monotone function $F(t)$, and a careful asymptotic analysis of $b$-level sets, tying curvature, volume growth, and topology together in nonparabolic, nonnegatively curved manifolds.
Abstract
We prove the general sharp mean value inequality for non-negative superharmonic functions and its corresponding rigidity, which removes the radius restriction of Schoen-Yau's classical result about this inequality. And we obtain an explicit formula of the asymptotic scaling invariant integral of weighted scalar curvature, on three dimensional complete Riemannian manifolds with non-negative Ricci curvature and maximal volume growth. As an application, we use this formula to give another proof of Hamilton's pinching conjecture in this case.
