论文部分内容阅读
In this talk,we first review the recent progress on the study of convergence of multiple ergodic averages both in L2 norm and pointwisely.Then we show that if(X;X; μ; T)is a distal or weakly mixing PID measure preserving system,then for all d and all f1;...,fd ∈ L∞(X;X; μ),limN→∞1/N∑(N-1)(n=0)f1(Tnx)…fd(Tdnx)exists almost surely.