4
votes
1answer
300 views

Kadison-Singer problem in exotic Hilbert spaces

The Kadison-Singer problem is considered in relation to the separable Hilbert space: KS: Does every pure state on the diagonal (atomic) masa of $B(\ell_2)$ has a unique extension to $B(\ell_2)$? ...
1
vote
2answers
530 views

Do separable $C^*$-algebras form a set?

The question is in subject. Update: See Andreas Thom's answer.