Minimal volume and simplicial norm of visibility n-manifolds and compact 3-manifolds
arXiv:0812.3353
Abstract
Theorem A. Let denote a closed Riemannian manifold with nonpositive sectional curvature and let be the universal cover of with the lifted metric. Suppose that the universal cover contains no totally geodesic embedded Euclidean plane (i.e., is a visibility manifold). Then Gromov's simplicial volume is non-zero. Consequently, is non-collapsible while keeping Ricci curvature bounded from below. More precisely, if , then M^3K(π, 1)ΓΓ\mathbb{Z}\oplus \mathbb{Z}M^3\mathbb{H}^3M^3 \equiv \mathbb{H}^3/ΓMinVol(M^3) \ge {1/24}\| M^3 \| > 0$. Minimal volume and simplicial norm of all other compact 3-manifolds without boundary and {\it singular} spaces will also be discussed.
In this updated version, we were able to extend our results on smooth visibility manifolds to possibly singular visibility spaces by using a result of Martin Bridson