The authors study complete open manifolds whose curvature is non-negative along ray directions. They prove that such manifold has infinite volume. Cheeger-Gromoll’s splitting theorem is generallied. They also study topology of such manifolds.
机构:
Fudan Univ, Sch Math Sci, Shanghai 200433, Peoples R China
Univ Calif Riverside, Dept Math, Riverside, CA 92521 USAFudan Univ, Sch Math Sci, Shanghai 200433, Peoples R China
机构:
Nantong Normal Coll, Dept Math & Phys, 24 Chengshan Rd, Nantong 226001, Jiangsu, Peoples R ChinaNantong Normal Coll, Dept Math & Phys, 24 Chengshan Rd, Nantong 226001, Jiangsu, Peoples R China