Fluctuations of ergodic averages for amenable group actions
Groups, geometry, and dynamics, Tome 15 (2021) no. 3, pp. 1041-1058
Voir la notice de l'article provenant de la source EMS Press
We show that for any countable amenable group action, along certain Følner sequences (those that have for any c>1 a two-sided c-tempered tail), one has a universal estimate for the number of fluctuations in the ergodic averages of L∞ functions. This estimate gives exponential decay in the number of fluctuations. Any two-sided Følner sequence can be thinned out to satisfy the above property. In particular, any countable amenable group admits such a sequence. This extends results of S. Kalikow and B. Weiss [1] for Zd actions and of N. Moriakov [3] for actions of groups with polynomial growth.
Classification :
28-XX
Mots-clés : Ergodic theorems, upcrossing inequalities, amenable group actions
Mots-clés : Ergodic theorems, upcrossing inequalities, amenable group actions
Affiliations des auteurs :
Uri Gabor  1
Uri Gabor. Fluctuations of ergodic averages for amenable group actions. Groups, geometry, and dynamics, Tome 15 (2021) no. 3, pp. 1041-1058. doi: 10.4171/ggd/622
@article{10_4171_ggd_622,
author = {Uri Gabor},
title = {Fluctuations of ergodic averages for amenable group actions},
journal = {Groups, geometry, and dynamics},
pages = {1041--1058},
year = {2021},
volume = {15},
number = {3},
doi = {10.4171/ggd/622},
url = {http://geodesic.mathdoc.fr/articles/10.4171/ggd/622/}
}
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