Skip to main content
7 events
when toggle format what by license comment
Dec 18, 2012 at 3:00 comment added Clark Thank you, I had bad luck finding this with a few Riemannian geometry texts and I flipped through do Carmo's book and somehow missed this result, which is proven in the text.
Dec 18, 2012 at 1:22 history edited Rami
edited tags
Dec 17, 2012 at 21:51 comment added Ian Agol This question is probably more appropriate for Math.stackexchange - you can find the answer in many Riemannian geometry textbooks.
Dec 17, 2012 at 19:01 history edited Pablo Lessa
edited tags
Dec 17, 2012 at 8:04 comment added Misha This is an easy corollary of the "flat strip" theorem: If $X$ is a CAT(0) space and $g_1, g_2$ are two geodesics in $X$ which are Hausdorff-close, then $g_1, g_2$ cobound a flat strip in $X$. You can also take a look at do Carmo's book "Riemannian geometry", I think there is a proof there.
Dec 17, 2012 at 8:04 comment added Dan Fox This result is a special case of the following more general result of Eells and Sampson (see Theorem B in the last section of "Harmonic mappings of Riemannian manifolds") that any continuous map between closed Riemannian manifolds $M$ and $N$ where $M$ has nonnegative Ricci curvature and $N$ has nonpositive sectional curvature is homotopic to a totally geodesic map; if, moreover, $N$ has somewhere strictly negative curvature, then the map is either null-homotopic or homotopic to a closed geodesic. Any survey on harmonic mappings should contain some version of this.
Dec 17, 2012 at 7:05 history asked Clark CC BY-SA 3.0