EN
For a given linear operator T in a complex Banach space X and α ∈ ℂ with ℜ (α) > 0, we define the nth Cesàro mean of order α of the powers of T by $Mₙ^{α} = (Aₙ^{α})^{-1} ∑_{k=0}^{n} A_{n-k}^{α-1}T^{k}$. For α = 1, we find $Mₙ¹ = (n+1)^{-1} ∑_{k=0}^{n}T^{k}$, the usual Cesàro mean. We give necessary and sufficient conditions for a (C,α) bounded operator to be (C,α) strongly (weakly) ergodic.