PreprintCC BY-NC-ND 4.0arXiv
Numerical index one characterises commutative JB*-triples
Abstract
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 question left open in the literature since 2008.
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BibTeX
@misc{li2026numerical,
title = {{Numerical index one characterises commutative JB*-triples}},
author = {Lei Li and Siyu Liu and Antonio M. Peralta},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.07710},
eprint = {2609.07710},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.07710},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Numerical index one characterises commutative JB*-triples
AU - Lei Li
AU - Siyu Liu
AU - Antonio M. Peralta
PY - 2026
DA - 2026/09/07
PB - arXiv
DO - 10.48550/arxiv.2609.07710
UR - https://arxiv.org/abs/2609.07710
AB - 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 question left open in the literature since 2008.
ER -