Distance to regular elements and polar decompositions in a C*-algebra

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autor principal: Thiel, Hannes
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866915639233347584
author Thiel, Hannes
author_facet Thiel, Hannes
contents We show that the distance from an element of a C*-algebra to the set of regular elements is the infimum of the $δ>0$ for which the $δ$-cut-down of the element admits a polar decomposition within the algebra. This parallels results of Pedersen and Brown-Pedersen describing the distance to invertible and quasi-invertible elements through polar decompositions of cut-downs whose polar parts are unitaries or extreme partial isometries.
format Preprint
id arxiv_https___arxiv_org_abs_2511_21391
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Distance to regular elements and polar decompositions in a C*-algebra
Thiel, Hannes
Operator Algebras
Primary 46L05, Secondary 47C15, 47A63
We show that the distance from an element of a C*-algebra to the set of regular elements is the infimum of the $δ>0$ for which the $δ$-cut-down of the element admits a polar decomposition within the algebra. This parallels results of Pedersen and Brown-Pedersen describing the distance to invertible and quasi-invertible elements through polar decompositions of cut-downs whose polar parts are unitaries or extreme partial isometries.
title Distance to regular elements and polar decompositions in a C*-algebra
topic Operator Algebras
Primary 46L05, Secondary 47C15, 47A63
url https://arxiv.org/abs/2511.21391