Timeline for The kernel of all invariant means
Current License: CC BY-SA 4.0
12 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 7, 2022 at 14:27 | history | edited | LSpice | CC BY-SA 4.0 |
Proofreading; use Markdown, not MathJax, for bold
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| Mar 7, 2022 at 13:17 | history | edited | YCor | CC BY-SA 4.0 |
\cap->\bigcap
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| Jun 7, 2017 at 16:50 | vote | accept | ARG | ||
| Jun 5, 2017 at 12:56 | answer | added | YCor | timeline score: 3 | |
| Jun 5, 2017 at 12:13 | answer | added | onur | timeline score: 0 | |
| Aug 19, 2012 at 10:08 | comment | added | ARG | Thanks for the comments and references, it makes a good enough answer for me too! | |
| Aug 18, 2012 at 17:58 | comment | added | user6976 | @Narutaka: Your answer is good enough for me. I do not know about Antoine. | |
| Aug 18, 2012 at 16:05 | comment | added | Narutaka OZAWA | @Mark: I'm not sure if this is explicit enough, but take any Folner sequence $F_n$. Then, $f$ has mean zero iff $\lim_{n\to\infty}\sup_{x\in G}|\sum_{y\in F_nx}f(y)|/|F_n|=0$. $\because$ If it's nonzero, then the uniform measure on $F_nx_n$ tends to an invariant mean which is nonzero at $f$. The converse follows from the fact that $f_n(x):=\sum_{y\in F_nx}f(y)/|F_n|$ has the same mean as $f$. | |
| Aug 18, 2012 at 13:41 | comment | added | Alain Valette | Is this MO question useful to you? mathoverflow.net/questions/65325/… | |
| Aug 18, 2012 at 13:07 | comment | added | user6976 | Did you compute it for $\mathbb{Z}$? | |
| Aug 18, 2012 at 13:06 | comment | added | Narutaka OZAWA | The trivial answer would be the closed linear span of $\lbrace f-\lambda_g(f) : g \in G,\ f\in\ell_\infty G\rbrace$. | |
| Aug 18, 2012 at 12:08 | history | asked | ARG | CC BY-SA 3.0 |