2003/11/17 by Idris Assani, Assani, Idris
Mathematics · #37A30 #Dynamical Systems (math.DS) #FOS: Mathematics #math.DS #msc:37A30
paper · pdf · doi:10.48550/arxiv.math/0311274
14 pages
arxiv created 2003/11/17 · arxiv updated 2009/12/01
Let (X, B, μ) be a probability measure space and T1, T2, T3 three not necessarily commuting measure preserving transformations on (X, B, μ). We prove that for all bounded functions f1, f2, f3 the averages (1)/(N2)∑n, m =1N f1(T1nx)f2(T2mx)f3(T3n+mx) converges a.e. Generalizations to averages of 2k -1 functions are also given for not necessarily commuting weakly mixing systems.