The class f of almost convergent sequences was introduced by G.G. Lorentz, using the idea of the Banach limits [A contribution to the theory of divergent sequences, Acta Math. 80(1948), 167-190]. Let fo(B) and f(...The class f of almost convergent sequences was introduced by G.G. Lorentz, using the idea of the Banach limits [A contribution to the theory of divergent sequences, Acta Math. 80(1948), 167-190]. Let fo(B) and f(B) be the domain of the double sequential band matrix B(r, s) in the sequence spaces f0 and f. In this article, the β- and γ-duals of the space f(B) are determined. Additionally, we give some inclusion theorems concerning with the spaces f0(B) and f(β). Moreover, the classes (f(B) : μ) and (μ: f(B)) of infinite matrices are characterized, and the characterizations of some other classes are also given as an application of those main results, where μ is an arbitrary sequence space.展开更多
文摘The class f of almost convergent sequences was introduced by G.G. Lorentz, using the idea of the Banach limits [A contribution to the theory of divergent sequences, Acta Math. 80(1948), 167-190]. Let fo(B) and f(B) be the domain of the double sequential band matrix B(r, s) in the sequence spaces f0 and f. In this article, the β- and γ-duals of the space f(B) are determined. Additionally, we give some inclusion theorems concerning with the spaces f0(B) and f(β). Moreover, the classes (f(B) : μ) and (μ: f(B)) of infinite matrices are characterized, and the characterizations of some other classes are also given as an application of those main results, where μ is an arbitrary sequence space.