2022/05/09 by Ontaneda, Pedro, Ricks, Russell
#Dynamical Systems (math.DS) #FOS: Mathematics #Metric Geometry (math.MG)
paper · doi:10.48550/arxiv.2205.04377
Let X be a proper, geodesically complete CAT(0) space which satisfies Chen and Eberlein's duality condition. We show the existence of a strong notion of rank for X by proving that the parallel sets Pv of geodesics v in X are generically flat. More precisely, let GX be the space of parametrized unit-speed geodesics in X. There is a unique k and a dense Gδ set A in GX such that Pv is isometric to flat Euclidean space ℝk, for all v ∈ A. It follows that ℝk isometrically embeds in Pv for every v ∈ GX.