Timeline for "Minimal" group C*-algebra?
Current License: CC BY-SA 3.0
5 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jul 7, 2014 at 11:56 | vote | accept | Matthew Daws | ||
| Jul 4, 2014 at 18:33 | answer | added | Yemon Choi | timeline score: 9 | |
| Jun 26, 2014 at 22:01 | comment | added | Caleb Eckhardt | Aaron, there's no minimal C*-norm on $\mathbb{C}[\Gamma]$ in general. Take for example $\Gamma=\mathbb{Z}.$ Let $I_n$ be a decreasing sequence of subarcs of the circle with intersection a single point $\omega.$ The representations (call them $\pi_n$) corresponding to restriction to the $I_n$ are all injective on $\mathbb{C}[\mathbb{Z}].$ But any polynomial $p$ that has $\omega$ as a root will have $||\pi_n(p)||\rightarrow p(\omega)=0.$ | |
| Jun 26, 2014 at 21:04 | comment | added | Aaron Tikuisis | What about if in place of $\ell^1(\Gamma)$, we just take the group algebra $\mathbb C[\Gamma]$. Can there be a smaller completion in that case? | |
| Jun 24, 2014 at 10:45 | history | asked | Matthew Daws | CC BY-SA 3.0 |