A simplified formula for the matched projection of an idempotent

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Xu, Qingxiang
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908699017084928
author Xu, Qingxiang
author_facet Xu, Qingxiang
contents Let $\mathcal{L}(H)$ be the set of all adjointable operators on a Hilbert $C^*$-module $H$. For each $T\in\mathcal{L}(H)$, $T^*$ denotes its adjoint operator, and $|T^*|$ is the positive square root of $TT^*$. We establish a simplified formula for the matched projection $m(Q)$ of an idempotent $Q\in\mathcal{L}(H)$ as $$m(Q)=\frac{I+|Q^*|-|I-Q^*|}{2},$$ where $I$ is the identity operator on $H$. This explicit expression allows for the direct derivation of some basic properties of $m(Q)$.
format Preprint
id arxiv_https___arxiv_org_abs_2512_05970
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A simplified formula for the matched projection of an idempotent
Xu, Qingxiang
Functional Analysis
Let $\mathcal{L}(H)$ be the set of all adjointable operators on a Hilbert $C^*$-module $H$. For each $T\in\mathcal{L}(H)$, $T^*$ denotes its adjoint operator, and $|T^*|$ is the positive square root of $TT^*$. We establish a simplified formula for the matched projection $m(Q)$ of an idempotent $Q\in\mathcal{L}(H)$ as $$m(Q)=\frac{I+|Q^*|-|I-Q^*|}{2},$$ where $I$ is the identity operator on $H$. This explicit expression allows for the direct derivation of some basic properties of $m(Q)$.
title A simplified formula for the matched projection of an idempotent
topic Functional Analysis
url https://arxiv.org/abs/2512.05970