Crosscap Stability
We provide an alternative proof that Crosscaps are diffeomorphically stable.
math.DG↗
arXiv subjects
Publications and source records attributed to Michael Sill.
We provide an alternative proof that Crosscaps are diffeomorphically stable.
The smallest $r$ so that a metric $r$-ball covers a metric space $M$ is called the radius of $M$. The volume of a metric $r$-ball in the space form of constant curvature $k$ is an upper bound for the volume of any Riemannian manifold with sectional curvature $\geq k$ and radius $\leq r$. We show that when such a manifold has volume almost equal to this upper bound, it is diffeomorphic to a sphere or a real projective space.