English

Extending positive definiteness

Functional Analysis 2009-07-01 v1

Abstract

The main result of the paper gives criteria for extendibility of sesquilinear form-valued mappings defined on symmetric subsets of *-semigroups to positive definite ones. By specifying this we obtain new solutions of: * the truncated complex moment problem, * the truncated multidimensional trigonometric moment problem, * the truncated two-sided complex moment problem, as well as characterizations of unbounded subnormality and criteria for the existence of unitary power dilation.

Keywords

Cite

@article{arxiv.0906.5410,
  title  = {Extending positive definiteness},
  author = {D. Cichoń and J. Stochel and F. H. Szafraniec},
  journal= {arXiv preprint arXiv:0906.5410},
  year   = {2009}
}
R2 v1 2026-06-21T13:19:14.594Z