11 citations · 17 across the 8 of their papers we have counts for
5 papers · 1 filter
Lower curvature bounds on metric surfaces via the Bishop--Gromov inequality
Alexander Lytchak, Stephan Stadler
We characterize lower curvature bounds on metric surfaces by the Bishop--Gromov inequality for metric balls.
Rank Rigidity for CAT(0) spaces without 3-flats
Stephan Stadler
If a group acts geometrically on a CAT(0) space without 3-flats, then either contains a -periodic geodesic which does not bound a flat half-plane, or else is a r…
CAT(0) spaces of higher rank I
Stephan Stadler
A CAT(0) space has rank at least if every geodesic lies in an -flat. Ballmann's Higher Rank Rigidity Conjecture predicts that a CAT(0) space of rank at least with a geom…
Affine functions on Alexandrov spaces
Christian Lange, Stephan Stadler
We show that every finite-dimensional Alexandrov space X with curvature bounded from below embeds canonically into a product of an Alexandrov space with the same curvature bound an…
An obstruction to the smoothability of singular nonpositively curved metrics on 4-manifolds by patterns of incompressible tori
Stephan Stadler
We give new examples of closed smooth 4-manifolds which support singular metrics of nonpositive curvature, but no smooth ones, thereby answering affirmatively a question of Gromov.…