Axes in Outer Space

dc.creatorHandel, Michael
dc.creatorMosher, Lee
dc.date2006-05-13
dc.date2006-07-03
dc.date.accessioned2026-07-07T07:14:11Z
dc.date.available2026-07-07T07:14:11Z
dc.descriptionWe develop a notion of axis in the Culler--Vogtmann outer space X_r of a finite rank free group F_r, with respect to the action of a nongeometric, fully irreducible outer automorphism phi. Unlike the situation of a loxodromic isometry acting on hyperbolic space, or a pseudo-Anosov mapping class acting on Teichmuller space, X_r has no natural metric, and phi seems not to have a single natural axis. Instead our axes for phi, while not unique, fit into an ``axis bundle'' A_phi with nice topological properties: A_phi is a closed subset of X_r proper homotopy equivalent to a line, it is invariant under phi, the two ends of A_phi limit on the repeller and attractor of the source--sink action of phi on compactified outer space, and A_phi depends naturally on the repeller and attractor. We propose various definitions for A_phi, each motivated in different ways by train track theory or by properties of axes in Teichmuller space, and we prove their equivalence.
dc.description96 pages. Version 2: The example of Section 3.4 has been corrected, and now has an even more interesting ideal Whitehead graph
dc.identifierhttps://arxiv.org/abs/math/0605355
dc.identifierhttp://arxiv.org/abs/math/0605355
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/112775
dc.subjectGroup Theory
dc.subject20F65 57M07
dc.titleAxes in Outer Space
dc.typetext

Files

Collections