Siyu Liu

activity

20242026

collaborators

5 papers

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.FA2026

A Le Page--Kaplansky theorem characterizing commutative JB*-triples

Lei Li, Siyu Liu, Antonio M. Peralta

We prove that a Le Page-type inequality is also valid for metrically characterizing those JB $^{*}$ -triples that are commutative. More precisely, we establish that the following state…

math.FA2025

An algebraic characterization of linearity for additive maps preserving orthogonality

Lei Li, Siyu Liu, Antonio M. Peralta

We study when an additive mapping preserving orthogonality between two complex inner product spaces is automatically complex-linear or conjugate-linear. Concretely, let $H$ and $K$ …

math.OA2024

Characterization of minimal tripotents via annihilators and its application to the study of additive preservers of truncations

Lei Li, Siyu Liu, Antonio M. Peralta

The contributions in this note begin with a new characterization of (positive) scalar multiples of minimal tripotents in a general JB $^{*}$ -triple $E$ , proving that a non-zero elemen…

math.FA2024

Additive mappings preserving orthogonality between complex inner product spaces

Lei Li, Siyu Liu, Antonio M. Peralta

Let $H$ and $K$ be two complex inner product spaces with dim $(X) \geq 2$ . We prove that for each non-zero additive mapping $A : H \to K$ with dense image the following statements are…