Spheres in the curve complex
Geometric Topology
2012-05-01 v2 Metric Geometry
Abstract
In this paper we study the geometry of metric spheres in the curve complex of a surface, with the goal of determining the "average" distance between points on a given sphere. Averaging is not technically possible because metric spheres in the curve complex are countably infinite and do not support any invariant probability measures. To make sense of the idea of averaging, we instead develop definitions of null and generic subsets in a way that is compatible with the topological structure of the curve complex. With respect to this notion of genericity, we show that pairs of points on a sphere of radius R almost always have distance exactly 2R apart, which is as large as possible.
Cite
@article{arxiv.1109.6338,
title = {Spheres in the curve complex},
author = {Spencer Dowdall and Moon Duchin and Howard Masur},
journal= {arXiv preprint arXiv:1109.6338},
year = {2012}
}
Comments
Main definition simplified; exposition improved