English

On the Shirshov--Cohn theorem for JB-algebras

Operator Algebras 2026-05-26 v1 Functional Analysis

Abstract

It is shown that a JB-algebra which can be generated by the union of two of its associative Jordan subalgebras is a JC-algebra, hence special. A similar refinement of Macdonald's principle for JB-algebras is obtained. Moreover, we prove that the free unital JB-algebra generated by nn projections is a JC-algebra if and only if n{1,2,3}n\in \{1,2,3\}. Finally, we give an explicit description of the free unital JB-algebra generated by two projections paralleling the Raeburn-Sinclair theorem for C*-algebras.

Keywords

Cite

@article{arxiv.2605.24427,
  title  = {On the Shirshov--Cohn theorem for JB-algebras},
  author = {Mark Roelands and Samuel Tiersma},
  journal= {arXiv preprint arXiv:2605.24427},
  year   = {2026}
}