English

On decomposition for pairs of twisted contractions

Functional Analysis 2024-04-11 v2 Operator Algebras

Abstract

This paper presents Wold-type decomposition for various pairs of twisted contractions on Hilbert spaces. As a consequence, we obtain Wold-type decomposition for pairs of doubly twisted isometries and in particular, new and simple proof of S\l{}o\'{c}inski's theorem for pairs of doubly commuting isometries are provided. We also achieve an explicit decomposition for pairs of twisted contractions such that the c.n.u. parts of the contractions are in C00C_{00}. It is shown that for a pair (T,V)(T,V^*) of twisted operators with TT as a contraction and VV as an isometry, there exists a unique (upto unitary equivalence) pair of doubly twisted isometries on the minimal isometric dilation space of TT. As an application, we prove that pairs of twisted operators consisting of an isometry and a co-isometry are doubly twisted. Finally, we have given a characterization for pairs of doubly twisted isometries.

Keywords

Cite

@article{arxiv.2208.04737,
  title  = {On decomposition for pairs of twisted contractions},
  author = {Satyabrata Majee and Amit Maji},
  journal= {arXiv preprint arXiv:2208.04737},
  year   = {2024}
}

Comments

29 pages. Revised and section 6 is added