Filomat, cilt.36, sa.15, ss.5323-5335, 2022 (SCI-Expanded, Scopus)
A = (ank) be a regular summability matrix. In the present paper we deal with subspaces of the space of A−statistically convergent sequences obtained by the rate at which the A−statistical limit tends to zero. We prove that a sequence is the A−strongly convergent if and only if it is the A−statistically convergent and the A−uniformly integrable with the rate of o (an ) where a = (an ) is a positive nonincreasing sequence. We also make a link between the A−strong convergence and the A−distributional convergence with the rate of o (an ). Finally, as an application we present an approximation theorem of Korovkin type.