English

Sequences of operators, monotone in the sense of contractive domination

Functional Analysis 2024-01-02 v1

Abstract

A sequence of operators TnT_n from a Hilbert space H{\mathfrak H} to Hilbert spaces Kn{\mathfrak K}_n which is nondecreasing in the sense of contractive domination is shown to have a limit which is still a linear operator TT from H{\mathfrak H} to a Hilbert space K{\mathfrak K}. Moreover, the closability or closedness of TnT_n is preserved in the limit. The closures converge likewise and the connection between the limits is investigated. There is no similar way of dealing directly with linear relations. However, the sequence of closures is still nondecreasing and then the convergence is governed by the monotonicity principle. There are some related results for nonincreasing sequences.

Keywords

Cite

@article{arxiv.2401.00312,
  title  = {Sequences of operators, monotone in the sense of contractive domination},
  author = {Seppo Hassi and Henk de Snoo},
  journal= {arXiv preprint arXiv:2401.00312},
  year   = {2024}
}

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22 pages