Journal of Inequalities and Applications 
Volume 2007 (2007), Article ID 10892, 10 pages
doi:10.1155/2007/10892
Research Article

On General Summability Factor Theorems

Ekrem Savaş

 Department of Mathematics, Faculty of Science and Arts, Istanbul Ticaret University, Uskudar, Istanbul 34672, Turkey
Received 17 August 2006; Revised 6 December 2006; Accepted 2 January 2007

Recommended by Ram Mohapatra

Abstract

The goal of this paper is to obtain sufficient and (different) necessary conditions for a series ∑an, which is absolutely summable of order k by a triangular matrix method A, 1<k≤s<∞, to be such that ∑anλn is absolutely summable of order s by a triangular matrix method B. As corollaries, we obtain two inclusion theorems.