Skip to main content
9 events
when toggle format what by license comment
Dec 4, 2020 at 17:55 comment added user167952 You can probably help with this, if you are interested and have some spare time: mathoverflow.net/questions/378143/… Thanks in any case!
Dec 2, 2020 at 15:29 comment added user167952 I think I understand now! Thanks again :)
Dec 2, 2020 at 15:16 comment added Matthew Daws I'm not using that; I'm proving that...! In the penultimate paragraph, I use that this relation holds on $\mathcal B_0(H) \otimes A$. This is obvious. That is extends to the multiplier algebra is not obvious, and that's what my (sketchy) argument proves.
Dec 2, 2020 at 13:59 comment added user167952 I had a detailed look at your answer and I think you are just sweeping the technical parts under the identification carpet. It still looks like you are implicitely using something like $(id_H \otimes \Delta)(\tau_\alpha v_\alpha) = \tau_\alpha(id_{H_\alpha} \otimes \Delta)(v_\alpha)$ where $\tau_\alpha$ is the inclusion map $B(H_\alpha \otimes K) \to B(H \otimes K)$ on the left and similarly $\tau_\alpha: B(H_\alpha \otimes K \otimes K) \to B(H \otimes K \otimes K)$ on the right. This was exactly my question, so maybe I am just misunderstanding your answer.
Dec 2, 2020 at 12:50 comment added user167952 Was just a little bit of unsure :) Thanks for the confirmation!
Dec 2, 2020 at 12:38 comment added Matthew Daws Erm, yes! Not sure what else to say.
Dec 2, 2020 at 12:08 comment added user167952 Thanks! One more question: don't we actually need that $\sup_i \| v_i\| < \infty$ to define the direct sum? Otherwise $\bigoplus v_i$ won't be a bounded operator I think. Of course, in practise the representations are unitary and then this is no problem?
Dec 1, 2020 at 14:03 vote accept CommunityBot
Nov 30, 2020 at 15:47 history answered Matthew Daws CC BY-SA 4.0