Non-expanding maps and Busemann functions

Authors
Citation
A. Karlsson, Non-expanding maps and Busemann functions, ERGOD TH DY, 21, 2001, pp. 1447-1457
Citations number
23
Categorie Soggetti
Mathematics
Journal title
ERGODIC THEORY AND DYNAMICAL SYSTEMS
ISSN journal
01433857 → ACNP
Volume
21
Year of publication
2001
Part
5
Pages
1447 - 1457
Database
ISI
SICI code
0143-3857(200110)21:<1447:NMABF>2.0.ZU;2-N
Abstract
We give stronger versions and alternative simple proofs of some results of Beardon, [Be1] and [Be2]. These results concern contractions of locally com pact metric spaces and generalize the theorems of Wolff and Denjoy about th e iteration of a holomorphic map of the unit disk. In the case of unbounded orbits, there are two types of statements which can sometimes be proven; f irst, about invariant horoballs, and second, about the convergence of the i terates to a point on the boundary. A few further remarks of similar type a re made concerning certain random products of sernicontractions and also co ncerning semicontractions of Gromov hyperbolic spaces.