Abstract and Applied Analysis (Jan 2011)
The Cesáro Core of Double Sequences
Abstract
We have characterized a new type of core for double sequences, 𝑃𝐶-core, and determined the necessary and sufficient conditions on a four-dimensional matrix 𝐴 to yield 𝑃𝐶-core{𝐴𝑥}⊆𝛼(𝑃-core{𝑥}) for all ℓ∞2.