Isometry groups of simply connected manifolds of nonpositive curvature
نویسندگان
چکیده
منابع مشابه
Simply Connected Manifolds of Positive Scalar Curvature
Hitchin proved that if M is a spin manifold with positive scalar curvature, then the A^O-characteristic number a(M) vanishes. Gromov and Lawson conjectured that for a simply connected spin manifold M of dimension > 5, the vanishing of a(M) is sufficient for the existence of a Riemannian metric on M with positive scalar curvature. We prove this conjecture using techniques from stable homotopy th...
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where |B| is the length of second fundamental form. |B|2 = 4|H|2 − 2K, where H is the mean curvature and K is the Gauss curvature. The curvature of minimal surfaces is nonpositive. Then we exam what is still hold for some minimal surface theorems if extending the minimal condition H ≡ 0 to the surfaces with K ≤ 0 and (1). In 2001, F. Xavier [18] has the following theorem: Theorem [Xavier]. Let ...
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ژورنال
عنوان ژورنال: Illinois Journal of Mathematics
سال: 1980
ISSN: 0019-2082
DOI: 10.1215/ijm/1256047798