Matrix Transformations in the Sets $\chi(\overline{N}_p\overline{N}_q)$ Where $\chi$ Is of the Form $s_\xi$, or $s^\circ_\xi$, or $s_\xi^{(c)}$


Bruno De Malafosse, Eberhard Malkowsky




In this paper we deal with matrix transformations mapping in either of the sets $s_\alpha(\overline{N}_q)$, $s_\alpha^\circ(\overline{N}_q)$ or $s_\alpha^{(c)}(\overline{N}_q)$. Then we study some properties of the sets $s_\alpha(\overline{N}_p\overline{N}_q)$ and $s_\alpha^\circ(\overline{N}_p\overline{N}_q)$ and give a characterization of matrix transformations in these spaces. These results generalize those given in [11, 14, 16].