Antonio M. Peralta

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20242026

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3 papers · 2 filters

math.OA2026

Numerical index one characterises commutative JB*-triples

Lei Li, Siyu Liu, Antonio M. Peralta

We establish that a JB $^{*}$ -triple $E$ is commutative if and only if its numerical index $n (E)$ is one. As a consequence, $n (E) = 1$ implies $n (E^{*}) = n (E^{**}) = 1$ . This settles a…

math.OA2026

Quadratic & additive mappings on operator commuting elements in JBW*-algebras

Gerardo M. Escolano, Jan Hamhalter, Antonio M. Peralta +1

Let $A$ and $B$ be JBW $^{*}$ -algebras whose sets of unitaries are denoted by $U (A)$ and $U (B)$ , respectively. We show…

math.OA2026

A metric characterization of projections among positive norm-One elements in unital C $^{*}$ -algebras

Antonio M. Peralta, Pedro Saavedra

We characterize projections among positive norm-one elements in unital C $^{*}$ -algebras in pure geometric terms determined by the norm of the underlying Banach space. Concretely, let…

Numerical index one characterises commutative JB*-triples

Quadratic & additive mappings on operator commuting elements in JBW*-algebras

A metric characterization of projections among positive norm-One elements in unital C∗-algebras

A metric characterization of projections among positive norm-One elements in unital C $^{*}$ -algebras