A geometric characterisation of real C*-algebras
arXiv:2403.12628 · doi:10.1007/s11425-016-5135-4
Abstract
We characterise the positive cone of a real C*-algebra geometrically. Given an open cone in a real Banach space , with closure , we show that is the interior of the positive cone of a unital real C*-algebra if and only if it is a Finsler symmetric cone with an orientable extension, which is equivalent to the condition that is, in an equivalent norm, the hermitian part of a unital real C*-algebra with positive cone .