CHARACTERIZATIONS OF ALMOST CONVERGENT SEQUENCES IN A HILBERT SPACE OR IN $L^p(T)$
CHARACTERIZATIONS OF ALMOST CONVERGENT SEQUENCES IN A HILBERT SPACE OR IN $L^p(T)$
In [Acta Math. 80(1948),167-190], G. G. Lorentz characterized almost convergent sequences in $\mathbb R$ (or in $\mathbb C$) in terms of the concept of uniform convergence of the de la Vallée-Poussin means. In this paper, we give a further study on such kind of convergence for any Hilbert space or …