本文研究曲率二次衰减的完备黎曼流形,证明了若它的直径增长满足小的线性增长条件,则其基本群是有限生成的.
In this paper, we prove that a complete Riemannian manifold Mn with lower quadratic sectional curvature (or Ricci curvature) decay, if it has small linear diameter growth, then it has a finitely generated fundamental group.