English

Weighted projections into closed subspaces

Functional Analysis 2013-05-29 v1 Operator Algebras

Abstract

In this paper we study AA-projections, i.e. operators of a Hilbert space \HH\HH which act as projections when a seminorm is considered in \HH\HH. AA-projections were introduced by Mitra and Rao \cite{[MitRao74]} for finite dimensional spaces. We relate this concept to the theory of compatibility between positive operators and closed subspaces of \HH\HH. We also study the relationship between weighted least squares problems and compatibility.

Keywords

Cite

@article{arxiv.1305.6357,
  title  = {Weighted projections into closed subspaces},
  author = {Gustavo Corach and Guillermina Fongi and Alejandra Maestripieri},
  journal= {arXiv preprint arXiv:1305.6357},
  year   = {2013}
}
R2 v1 2026-06-22T00:23:30.702Z