We propose the metric notion of strong hyperbolicity as a way of obtaining hyperbolicity with sharp additional properties. Specically, strongly hyperbolic spaces are Gromov hyperbolic spaces that are metrically well-behaved at infinity, and, under weak geodesic assumptions, they are strongly bolic as well. We show that CAT(–1) spaces are strongly hyperbolic. On the way, we determine the best constant of hyperbolicity for the standard hyperbolic plane H2. We also show that the Green metric defined by a random walk on a hyperbolic group is strongly hyperbolic. A measure-theoretic consequence at the boundary is that the harmonic measure defined by a random walk is a visual Hausdorff measure.
@article{10_4171_ggd_372,
author = {Bogdan Nica and J\'an \v{S}pakula},
title = {Strong hyperbolicity},
journal = {Groups, geometry, and dynamics},
pages = {951--964},
year = {2016},
volume = {10},
number = {3},
doi = {10.4171/ggd/372},
url = {http://geodesic.mathdoc.fr/articles/10.4171/ggd/372/}
}
TY - JOUR
AU - Bogdan Nica
AU - Ján Špakula
TI - Strong hyperbolicity
JO - Groups, geometry, and dynamics
PY - 2016
SP - 951
EP - 964
VL - 10
IS - 3
UR - http://geodesic.mathdoc.fr/articles/10.4171/ggd/372/
DO - 10.4171/ggd/372
ID - 10_4171_ggd_372
ER -