Weak $A$-frames and weak $A$-semi-frames
Authors : Jean Pierre ANTOINE, Giorgia BELLOMONTE, Camillo TRAPANI
Pages : 104-118
Doi:10.33205/cma.835582
View : 20 | Download : 7
Publication Date : 2021-03-01
Article Type : Research Paper
Abstract :After reviewing the interplay between frames and lower semi-frames, we introduce the notion of lower semi-frame controlled by a densely defined operator $A$ or, for short, a weak lower $A$-semi-frame and we study its properties. In particular, we compare it with that of lower atomic systems, introduced in insert ignore into journalissuearticles values(GB);. We discuss duality properties and we suggest several possible definitions for weak $A$-upper semi-frames. Concrete examples are presented.Keywords : A frames, weak upper and lower, A semi frames, lower atomic systems, G duality