© M. Başarir and M. Kayikçi. 2009
Received: 1 May 2009
Accepted: 17 July 2009
Published: 23 August 2009
We introduce the generalized Riesz difference sequence space which is defined by where is the Riesz sequence space defined by Altay and Başar. We give some topological properties, compute the duals, and determine the Schauder basis of this space. Finally; we study the characterization of some matrix mappings on this sequence space. At the end of the paper, we investigate some geometric properties of and we have proved that this sequence space has property for .
Let be the space of all real valued sequences. We write for the sequence spaces of all bounded, convergent, and null sequences, respectively. Also by , , and , we denote the sequence spaces of all convergent, absolutely and -absolutely, convergent series, respectively; where
Altay and Başar [1, 2] introduced the Riesz sequence space , and of nonabsolute type which is the set of all sequences whose -transforms are in the space , and respectively. Here and afterwards, will be used as a bounded sequence of strictly positive real numbers with and and denotes the collection of all finite subsets of where . The Riesz sequence space introduced in  by Altay and Başar is
The difference sequence spaces , and were first defined and studied by Kızmaz in  and studied by several authors, [4–9]. Başar and Altay  have studied the sequence space as the set of all sequences such that their -transforms are in the space ; that is,
The idea of difference sequences is generalized by Çolak and Et . They defined the sequence spaces:
Recently, Başarir and Öztürk  introduced the Riesz difference sequence space as follows:
Our main subject in the present paper is to introduce the generalized Riesz difference sequence space which consists of all the sequences such that their -transforms are in the space and to investigate some topological and geometric properties with respect to paranorm on this space.
2. Basic Facts and Definitions
In this section we give some definitions and lemmas which will be frequently used.
By we denote the class of all matrices such that Thus, if and only if the series on the right side of (2.1) converges for each and every and we have for all A sequence is said to be -summable to if converges to which is called as the -limit of
Now we give some lemmas which we need to prove our theorems.
Lemma 2.5 (see ).
Lemma 2.6 (see ).
Lemma 2.7 (see ).
Here are some topological properties of the generalized Riesz difference sequence space.
This can be easily obtained by [12, Theorem 5] so we omit the proof.
In the previous section; we show that the sequence space which is the space of all real sequences such that is a complete paranormed space. It is paranormed by for all where We recall that a paranormed space is total if implies Every total paranormed space becomes a linear metric space with the metric given by It is clear that is a total paranormed space.
In this section, we investigate some geometric properties of . First we give the definition of the property in a paranormed space and we will use the method in  to prove the property Consequently, we obtain that has property for
We would like to express our gratitude to the reviewer for his/her careful reading and valuable suggestions which improved the presentation of the paper.
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