e-core of double sequences

The Cesáro Core of Double Sequences

and Applied Analysis 3 where σ s σ σj−1 s . In this case, we write σ − limx . By V 2 σ , we denote the set of all σ-convergent and bounded double sequences. One can see that in contrast to the case for single sequences, a convergent double sequence need not be σ-convergent. But every bounded convergent double sequence is σ-convergent. So, c∞ 2 ⊂ V 2 σ ⊂ ∞ 2 . In the case σ i i 1, σ-convergence ...

Characterization of P-Core and Absolute Equivalence of Double Sequences

Generalized Statistical Convergence and Statistical Core of Double Sequences

In this paper we extend the notion of λ-statistical convergence to the (λ, μ)statistical convergence for double sequences x = (xjk). We also determine some matrix transformations and establish some core theorems related to our new space of double sequences Sλ,μ.

The σ-convergence and σ-core of double sequences

The σ -convergence and σ -core of a real bounded sequence were introduced in [R. Raimi, Invariant means and invariant matrix methods of summability, Duke Math. J. 30 (1963) 81–94] and [S.L. Mishra, B. Satapathy, N. Rath, Invariant means and σ -core, J. Indian Math. Soc. 60 (1984) 151–158], respectively. In this work, we extend these ideas to double sequences. c © 2006 Elsevier Ltd. All rights r...

Some matrix transformations and generalized core of double sequences

A four-dimensional matrix transformation is said to be regular if it maps every bounded-convergent double sequence into a convergent sequence with the same limit. Firstly, Robison [G.M. Robison, Divergent double sequences and series, Trans. Amer. Math. Soc. 28 (1926) 50–73] presented the necessary and sufficient conditions for regular matrix transformations of double sequences. In this paper, t...