Pour tout nombre entier , nous construisons un ensemble d’entiers qui est un ensemble de récurrence multiple à l’ordre mais pas à l’ordre . Cela étend une construction de Furstenberg qui a construit un ensemble de récurrence qui n’est pas un ensemble de 2-récurrence. Nous obtenons un résultat similaire pour la convergence des moyennes ergodiques multiples. Comme conséquence de notre construction, nous exhibons aussi un résultat combinatoire relié au théorème de Szemerédi.
For every , we produce a set of integers which is -recurrent but not -recurrent. This extends a result of Furstenberg who produced a -recurrent set which is not -recurrent. We discuss a similar result for convergence of multiple ergodic averages. We also point out a combinatorial consequence related to Szemerédi’s theorem.
@article{AIF_2006__56_4_839_0, author = {Frantzikinakis, Nikos and Lesigne, Emmanuel and Wierdl, M\'at\'e}, title = {Sets of $k$-recurrence but not $(k+1)$-recurrence}, journal = {Annales de l'Institut Fourier}, volume = {56}, year = {2006}, pages = {839-849}, doi = {10.5802/aif.2202}, zbl = {1123.37001}, mrnumber = {2266880}, language = {en}, url = {http://dml.mathdoc.fr/item/AIF_2006__56_4_839_0} }
Frantzikinakis, Nikos; Lesigne, Emmanuel; Wierdl, Máté. Sets of $k$-recurrence but not $(k+1)$-recurrence. Annales de l'Institut Fourier, Tome 56 (2006) pp. 839-849. doi : 10.5802/aif.2202. http://gdmltest.u-ga.fr/item/AIF_2006__56_4_839_0/
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