摘要

We show that for any integer n >= 3, there exists a positive number eta(n) depending only on n such that if M-n is a complete simply connected n-dimensional Riemannian manifold whose sectional curvature, Ricci curvature and volume satisfy the conditions K-M <= 1, Ric(M) >= (n + 2)/4 and 0 < V(M) < 2(1 + eta) V (B-3/4 pi), respectively, then the diameter of M-n is less than 3 pi/2.

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