Sharpening a gap theorem: nonnegative Ricci and small curvature concentration
摘要
We sharpen a gap theorem of Chan and Lee (Gap theorem on manifolds with small curvature concentration. arXiv:2312.07845v1) for nonnegative Ricci curvature manifolds that have positive asymptotic volume ratio and small enough scale-invariant integral curvature (so-called “curvature concentration"), by showing that the curvature concentration need only depend linearly on the asymptotic volume ratio. We prove the result by exhibiting a long-time Ricci flow solution with faster than 1/t curvature decay, which allows us to shift the limiting contradiction argument to time infinity and thus obtain an explicit bound on the size of the gap.