Topological Classification of 4-Dimensional Complete Intersections.
Fixed points of discrete nilpotent group actions on
We prove that for each integer there is an open neighborhood of the identity map of the 2-sphere , in topology such that: if is a nilpotent subgroup of with length of nilpotency, generated by elements in , then the natural -action on has nonempty fixed point set. Moreover, the -action has at least two fixed points if the action has a finite nontrivial orbit.
Two generalizations of Cheeger-Gromoll splitting theorem via Bakry-Emery Ricci curvature
In this paper, we prove two generalized versions of the Cheeger-Gromoll splitting theorem via the non-negativity of the Bakry-Émery Ricci curavture on complete Riemannian manifolds.
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