Correspondence of Kubo-Ando Means over Real Division Algebras and Linearization of Means

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Franco, Jose, Merino, Allan
Format: Preprint
Veröffentlicht: 2026
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866913166011662336
author Franco, Jose
Merino, Allan
author_facet Franco, Jose
Merino, Allan
contents In this paper, we establish a bijection between Kubo-Ando operator means defined on the cones $\mathscr{P}_{n}(\mathbb{H})$, $\mathscr{P}_{2n}(\mathbb{C})$, and $\mathscr{P}_{4n}(\mathbb{R})$. This correspondence is induced by the canonical embeddings relating quaternionic, complex, and real positive definite matrices. We investigate several structural and geometric properties preserved by these bijections, including compatibility with functional calculus, invariance under congruence transformations, and behavior with respect to natural metrics on these cones. As an application, we prove that every Kubo-Ando mean on $\mathscr{P}_{2}(\mathbb{D})$, where $\mathbb{D}\in\left\{\mathbb{R},\mathbb{C},\mathbb{H}\right\}$, admits an explicit affine expression in terms of the matrices involved. Using the embeddings above, we derive explicit formulas for operator means on special classes of real $4\times4$ positive definite matrices arising as images of the cones $\mathscr{P}_{2}(\mathbb{C})$ and $\mathscr{P}_{2}(\mathbb{H})$. In particular, we obtain trace-determinant formulas for the geometric mean in the real, complex, and quaternionic settings.
format Preprint
id arxiv_https___arxiv_org_abs_2605_27707
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Correspondence of Kubo-Ando Means over Real Division Algebras and Linearization of Means
Franco, Jose
Merino, Allan
Functional Analysis
Operator Algebras
Primary: 15A42, Secondary: 47A64, 15B48
In this paper, we establish a bijection between Kubo-Ando operator means defined on the cones $\mathscr{P}_{n}(\mathbb{H})$, $\mathscr{P}_{2n}(\mathbb{C})$, and $\mathscr{P}_{4n}(\mathbb{R})$. This correspondence is induced by the canonical embeddings relating quaternionic, complex, and real positive definite matrices. We investigate several structural and geometric properties preserved by these bijections, including compatibility with functional calculus, invariance under congruence transformations, and behavior with respect to natural metrics on these cones. As an application, we prove that every Kubo-Ando mean on $\mathscr{P}_{2}(\mathbb{D})$, where $\mathbb{D}\in\left\{\mathbb{R},\mathbb{C},\mathbb{H}\right\}$, admits an explicit affine expression in terms of the matrices involved. Using the embeddings above, we derive explicit formulas for operator means on special classes of real $4\times4$ positive definite matrices arising as images of the cones $\mathscr{P}_{2}(\mathbb{C})$ and $\mathscr{P}_{2}(\mathbb{H})$. In particular, we obtain trace-determinant formulas for the geometric mean in the real, complex, and quaternionic settings.
title Correspondence of Kubo-Ando Means over Real Division Algebras and Linearization of Means
topic Functional Analysis
Operator Algebras
Primary: 15A42, Secondary: 47A64, 15B48
url https://arxiv.org/abs/2605.27707