Skip to main content
5 events
when toggle format what by license comment
Jun 23, 2020 at 15:02 comment added Manuel Norman @NikWeaver Nice point! Indeed, my idea was to try to construct a particular rank one operator $K$ which could help to show the existence of a nontrivial invariant subspace, because as you noticed the use of any $K$ would probably be not so useful
Jun 23, 2020 at 14:57 comment added Nik Weaver That said, even if you don't solve the ISP you might well discover something interesting in this direction ...
Jun 23, 2020 at 14:55 comment added Nik Weaver Interesting post, but I'm skeptical that this approach will work. The existence of a compact operator with ${\rm rank}(TK - KT) \leq 2$ is trivial, so it's unlikely to be of much help. For instance, fix a unit vector and let $K$ be the orthogonal projection onto its span. Now you give me an arbitrary bounded operator $T$ and I notice that the commutator with my $K$ has rank at most 2. Would that really help me to show that $T$ has a nontrivial invariant subspace?
Jun 23, 2020 at 10:46 review First posts
Jun 23, 2020 at 11:26
Jun 23, 2020 at 10:43 history asked Manuel Norman CC BY-SA 4.0