5 papers
Finite tripotents and finite JBW-triples
Jan Hamhalter, Ondřej F. K. Kalenda, Antonio M. Peralta
We study two natural preorders on the set of tripotents in a JB-triple defined in terms of their Peirce decomposition and weaker than the standard partial order. We further int…
Measures of weak non-compactness in preduals of von Neumann algebras and JBW-triples
Jan Hamhalter, Ondřej F. K. Kalenda, Antonio M. Peralta +1
We prove, among other results, that three standard measures of weak non-compactness coincide in preduals of JBW-triples. This result is new even for preduals of von Neumann alg…
The order topology on duals of C-algebras and von Neumann algebras
Emmanuel Chetcuti, Jan Hamhalter
For a von Neumann algebra we study the order topology associated with the hermitian part and to intervals of the predual . It is shown t…
Noncommutative Vitali-Hahn-Saks Theorem holds precisely for finite -algebras
E. Chetcuti, J. Hamhalter
It is shown that the bona fide generalization of the Vitali-Hahn-Saks Theorem to von Neumann algebras is possible if, and only if, the algebra is finite. This settles the problem o…
Orthogonal Pure States in Operator Theory
Jan Hamhalter
We summarize and deepen recent results on systems of orthogonal pure states on operator algebras. Especially, we focus on noncommutative generalizations of some principles of topol…