Almost surjective ε-isometries of Banach spaces
We investigate Hyers-Ulam stability of non-surjective ε-isomeries of Banach spaces. We also pose and discuss an open problem.
Embeding weakly compact sets
Generalized atomic subspaces for operators in Hilbert spaces
We introduce the notion of a -atomic subspace for a bounded linear operator and construct several useful resolutions of the identity operator on a Hilbert space using the theory of -fusion frames. Also, we shall describe the concept of frame operator for a pair of -fusion Bessel sequences and some of their properties.
On a completion of prehilbertian spaces.