Matrix Transformations and Invariant Mean

Raimi [R. A. Raimi, Invariant means and invariant matrix methods of summability, Doke. Math. J.30 (1963), 81-94] gave a generalization of almost convergent and named it σ −convergent. In this paper we characterize the matrix classes (l(p, u), V∞) and (l(p, u), Vσ). (2000) Mathematics Subject Classification: 40C05; 40H05.