Abstract

For a double array of random variables {Xmn, m ≥ 1, n ≥ 1}, mean convergence theorems and weak laws of large numbers are established. For the mean convergence results, conditions are provided under which i=1kmj=1lnamnij(XijEXij)Lr0(0<r2) where {amnij;m,n,i,j1} are constants, and {kn,n1} and {ln,n1} are sequences of positive integers. The weak law results provide conditions for i=1Tmj=1τnamnij(XijEXij)p0 to hold where {Tm,m1} and {τn,n1} are sequences of positive integer-valued random variables. The sharpness of the results is illustrated by examples.