Operator E-norms and their use
Abstract
We consider a family of norms (called operator E-norms) on the algebra of all bounded operators on a separable Hilbert space induced by a positive densely defined operator on . Each norm of this family produces the same topology on depending on . By choosing different generating operator one can obtain operator E-norms producing different topologies, in particular, the strong operator topology on bounded subsets of . We obtain a generalised version of the Kretschmann-Schlingemann-Werner theorem, which shows continuity of the Stinespring representation of CP linear maps w.r.t. the energy-constrained -norm (diamond norm) on the set of CP linear maps and the operator E-norm on the set of Stinespring operators. The operator E-norms induced by a positive operator are well defined for linear operators relatively bounded w.r.t. the operator and the linear space of such operators equipped with any of these norms is a Banach space. We obtain explicit relations between the operator E-norms and the standard characteristics of -bounded operators. The operator E-norms allow to obtain simple upper bounds and continuity bounds for some functions depending on -bounded operators used in applications.
Cite
@article{arxiv.1806.05668,
title = {Operator E-norms and their use},
author = {M. E. Shirokov},
journal= {arXiv preprint arXiv:1806.05668},
year = {2021}
}
Comments
31 pages, in v.5 essential improvements and simplifications have been made by using the coincidence of two definitions of the operator E-norms proved in arXiv:2002.03969