Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-17T21:27:04.775Z Has data issue: false hasContentIssue false

A quantitative mean ergodic theorem for uniformly convex Banach spaces

Published online by Cambridge University Press:  17 March 2009

U. KOHLENBACH
Affiliation:
Department of Mathematics, Technische Universität Darmstadt, Schlossgartenstrasse 7, 64289 Darmstadt, Germany (email: kohlenbach@mathematik.tu-darmstadt.de)
L. LEUŞTEAN
Affiliation:
Department of Mathematics, Technische Universität Darmstadt, Schlossgartenstrasse 7, 64289 Darmstadt, Germany (email: kohlenbach@mathematik.tu-darmstadt.de) Institute of Mathematics ‘Simion Stoilow’ of the Romanian Academy, Calea Griviţei 21, PO Box 1-462, Bucharest, Romania (email: leustean@mathematik.tu-darmstadt.de)

Abstract

We provide an explicit uniform bound on the local stability of ergodic averages in uniformly convex Banach spaces. Our result can also be viewed as a finitary version in the sense of Tao of the mean ergodic theorem for such spaces and so generalizes similar results obtained for Hilbert spaces by Avigad et al [Local stability of ergodic averages. Trans. Amer. Math. Soc. to appear] and Tao [Norm convergence of multiple ergodic averages for commuting transformations. Ergod. Th. & Dynam. Sys.28(2) (2008), 657–688].

Type
Research Article
Copyright
Copyright © Cambridge University Press 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1]Avigad, J., Gerhardy, P. and Towsner, H.. Local stability of ergodic averages. Trans. Amer. Math. Soc. to appear.Google Scholar
[2]Birkhoff, G.. The mean ergodic theorem. Duke Math. J. 5(1) (1939), 1920.CrossRefGoogle Scholar
[3]Clarkson, J. A.. Uniformly convex spaces. Trans. Amer. Math. Soc. 40 (1936), 396414.CrossRefGoogle Scholar
[4]Gerhardy, P. and Kohlenbach, U.. General logical metatheorems for functional analysis. Trans. Amer. Math. Soc. 360 (2008), 26152660.CrossRefGoogle Scholar
[5]Kohlenbach, U.. Uniform asymptotic regularity for Mann iterates. J. Math. Anal. Appl. 279 (2003), 531544.CrossRefGoogle Scholar
[6]Kohlenbach, U.. Some logical metatheorems with application in functional analysis. Trans. Amer. Math. Soc. 357 (2005), 89128.CrossRefGoogle Scholar
[7]Kohlenbach, U.. Effective uniform bounds from proofs in abstract functional analysis. New Computational Paradigms: Changing Conceptions of What is Computable. Eds. B. Cooper, B. Löwe and A. Sorbi. Springer, Berlin, 2008, pp. 223258.CrossRefGoogle Scholar
[8]Kohlenbach, U.. Applied Proof Theory: Proof Interpretations and Their Use in Mathematics (Springer Monographs in Mathematics). Springer, Berlin, 2008.Google Scholar
[9]Kohlenbach, U. and Leuştean, L.. Asymptotically nonexpansive mappings in uniformly convex hyperbolic spaces. J. Eur. Math. Soc. to appear.Google Scholar
[10]Tao, T.. Soft analysis, hard analysis, and the finite convergence principle. Structures and Randomness: Pages from Year One of a Mathematical Blog. American Mathematical Society, Providence, RI, 2008.CrossRefGoogle Scholar
[11]Tao, T.. Norm convergence of multiple ergodic averages for commuting transformations. Ergod. Th. & Dynam. Sys. 28(2) (2008), 657688.CrossRefGoogle Scholar