Hostname: page-component-89b8bd64d-b5k59 Total loading time: 0 Render date: 2026-05-10T05:25:28.085Z Has data issue: false hasContentIssue false

A gap principle for dynamics

Published online by Cambridge University Press:  26 April 2010

Robert L. Benedetto
Affiliation:
Department of Mathematics, Amherst College, Amherst, MA 01002, USA (email: rlb@math.amherst.edu)
Dragos Ghioca
Affiliation:
Department of Mathematics & Computer Science, University of Lethbridge, 4401 University Drive, Lethbridge, AB T1K 3M4, Canada (email: dragos.ghioca@uleth.ca)
Pär Kurlberg
Affiliation:
Department of Mathematics, KTH, SE-100 44 Stockholm, Sweden (email: kurlberg@math.kth.se)
Thomas J. Tucker
Affiliation:
Department of Mathematics, Hylan Building, University of Rochester, Rochester, NY 14627, USA (email: ttucker@math.rochester.edu)
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the 'Save PDF' action button.

Let f1,…,fg∈ℂ(z) be rational functions, let Φ=(f1,…,fg) denote their coordinate-wise action on (ℙ1)g, let V ⊂(ℙ1)g be a proper subvariety, and let P be a point in (ℙ1)g(ℂ). We show that if 𝒮={n≥0:Φn(P)∈V (ℂ)} does not contain any infinite arithmetic progressions, then 𝒮 must be a very sparse set of integers. In particular, for any k and any sufficiently large N, the number of nN such that Φn(P)∈V (ℂ) is less than log kN, where log k denotes the kth iterate of the logfunction. This result can be interpreted as an analogue of the gap principle of Davenport–Roth and Mumford.

Information

Type
Research Article
Copyright
Copyright © Foundation Compositio Mathematica 2010