Endomorphisms of the Toeplitz algebra

This article describes all injective endomorphisms of the classical Toeplitz algebra. Their connection with endomorphisms of the algebra of continuous functions on the unit circle and with coverings over the unit circle was considered. It was shown that each non-unitary isometry V in the Toeplitz al...

Full description

Saved in:
Bibliographic Details
Main Authors: S. A. Grigoryan, A. Yu. Kuznetsova
Format: Article
Language:English
Published: Kazan Federal University 2023-11-01
Series:Учёные записки Казанского университета: Серия Физико-математические науки
Subjects:
Online Access:https://uzakufismat.elpub.ru/jour/article/view/5
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This article describes all injective endomorphisms of the classical Toeplitz algebra. Their connection with endomorphisms of the algebra of continuous functions on the unit circle and with coverings over the unit circle was considered. It was shown that each non-unitary isometry V in the Toeplitz algebra determines the identity preserving endomorphism, as well as the class of its compact perturbations, i.e., identity non-preserving endomorphisms, defined by partial isometries {V P}, where P is a projection of finite codimension. The notions of T -equivalence of endomorphisms and T -equivalence up to a compact perturbation were introduced. An example was provided wherein the isometries are unitarily equivalent but the corresponding endomorphisms fall into different equivalence classes. Of all endomorphisms, the ones belonging to the class of Blaschke endomorphisms, which are analogous to endomorphisms of the discalgebra and generate unbranched coverings over the unit circle, were singled out.
ISSN:2541-7746
2500-2198