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http://dx.doi.org/10.5831/HMJ.2012.34.2.273

A NOTE ON FOCAL POINT COMPARISON IN RIEMANNIAN GEOMETRY

Kim, Jong-Ryul (Department of Mathematics, Kunsan National University)

Publication Information

Honam Mathematical Journal / v.34, no.2, 2012 , pp. 273-278 More about this Journal

Abstract

Using a comparison of the Jacobi differential equations instead of volume comparison by Itokawa in [3], the focal radius is estimated under the suitable Ricci and mean curvature conditions.

Keywords

H-Jacobi tensor; Jacobi equation; Mean curvature;

Citations & Related Records

Reference

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5	Itokawa, Y.: Distance spheres and Myers-type theorems for manifolds with lower bounds on the Ricci curvature, Illinois J. Math. 34 (1990), no. 4, 693-705.
6	Kupeli, D. N.: On conjugate and focal points in semi-Riemannian geometry, Math. Z. 198 (1988), no. 4, 569-589. DOI