Osamu Hatori

activity

20232026

collaborators

4 papers

math.FA2026

Order isomorphisms on positive cones of non-unital $C^{*}$ -algebras

Osamu Hatori, Shiho Oi

Let $A$ and $B$ be $C^{*}$ -algebras, not necessarily unital, and let $T : A_{+} \to B_{+}$ be a positively homogeneous order isomorphism. We first prove that $T$ is additive and extends uni…

math.FA2026

Surjective Fischer--Muszély maps on positive cones of JB-algebras

Osamu Hatori, Shiho Oi

We prove that every surjective Fischer--Muszély map between positive cones of arbitrary JB-algebras is additive and positively homogeneous, and extends uniquely to a bounded positi…

math.OA2024

Non-linear characterization of Jordan $$ -isomorphisms via maps on positive cones of $C^{}$ -algebras

Osamu Hatori, Shiho Oi

We study maps between positive definite or positive semidefinite cones of unital $C^{*}$ -algebras. We describe surjective maps that preserve (1) the norm of the quotient or multiplic…

math.FA2023

Isometries between groups of invertible elements in Fourier-Stieltjes algebras

Osamu Hatori, Shiho Oi

We prove that if open subgroups of the groups of invertible elements in two Fourier-Stieltjes algebras are isometric as metric spaces, then the underlying locally compact groups ar…

Order isomorphisms on positive cones of non-unital C∗-algebras

Surjective Fischer--Muszély maps on positive cones of JB-algebras

Non-linear characterization of Jordan ∗-isomorphisms via maps on positive cones of C∗-algebras

Isometries between groups of invertible elements in Fourier-Stieltjes algebras

Order isomorphisms on positive cones of non-unital $C^{*}$ -algebras

Non-linear characterization of Jordan $$ -isomorphisms via maps on positive cones of $C^{}$ -algebras