Automatic continuity of biorthogonality preservers between weakly compact JB${}^{\ast }$-triples and atomic JBW${}^{\ast }$-triples

Abstract

We prove that every biorthogonality preserving linear surjection from a weakly compact JB${}^{\ast }$triple containing no infinite dimensional rank-one summands onto another JB${}^{\ast }$-triple is automatically continuous. We also show that every biorthogonality preserving linear surjection between atomic JBW${}^{\ast }$triples containing no infinite dimensional rank-one summands is automatically continuous. Consequently, two atomic JBW${}^{\ast }$-triples containing no rank-one summands are isomorphic if, and only if, there exists a (non necessarily continuous) biorthogonality preserving linear surjection between them.