2014/06/23 by Huang, Wen, Shao, Song, Ye, Xiangdong · 2 citations
#37A05 #37B05 #Dynamical Systems (math.DS) #FOS: Mathematics
paper · doi:10.48550/arxiv.1406.5930
By building some suitable strictly ergodic models, we prove that for an ergodic system (X,X,μ, T), d∈\mathbb N, f1, …, fd ∈ L∞(μ), the averages (1)/(N2) ∑(n,m)∈ [0,N-1]2 f1(Tnx)f2(Tn+mx)… fd(Tn+(d-1)mx) converge μ a.e. Deriving some results from the construction, for distal systems we answer positively the question if the multiple ergodic averages converge a.e. That is, we show that if (X,X,μ, T) is an ergodic distal system, and f1, …, fd ∈ L∞(μ), then multiple ergodic averages \frac 1 N∑n=0N-1f1(Tnx)… fd(Tdnx) converge μ a.e.