Skip to main content
3 events
when toggle format what by license comment
Mar 17, 2015 at 13:36 answer added Jeff Strom timeline score: 5
Mar 17, 2015 at 10:19 comment added Mark Grant If $X$ is a closed oriented $3$-manifold, then maps $X\to S^3$ are classified by their degree. Since the degree can be detected homologically, and since any multiplication $m:S^3\times S^3\to S^3$ must do the obvious thing on third homology, I think all the groups are isomorphic when $X$ is an oriented $3$-manifold. (I leave this comment in case anyone else was thinking of using Hopf's theorem.)
Mar 16, 2015 at 23:30 history asked user1437 CC BY-SA 3.0