The $\chi^{2}$ sequence spaces defined by a modulus


Nagarajan Subramanian, Umakanta Misra, Vladimir Rakočević




In this paper we introduce the following sequence spaces \begin{center}$\left\{x\in \chi^{2}: P-im_{k,\ell} um_{m=0}^{nfty} um_{n=0}^{nfty}a_{k\ell}^{mn}feft(eft(eft(m+n\right)!eft|x_{mn}\right|\right)^{\frac{1}{m+n}}\right)=0\right\}$ \end{center} and $\left\{x\in \Lambda^{2}: \sup_{k,\ell}\sum_{m=0}^{\infty}\sum_{m=0}^{\infty}a_{k \ell}^{mn}f\left(\left|x_{mn}\right|^{\frac{1}{m+n}}\right)< \infty\right\}$ where $f$ is a modulus function and $A$ is a nonnegative four dimensional matrix. We establish the inclusion theorems between these spaces and also general properties are discussed.