Timeline for Are the extremal points of a certain set of functions $\mathcal P(\mathbf N) \to \bf R$ weakly additive?
Current License: CC BY-SA 3.0
7 events
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| Apr 8, 2016 at 18:15 | comment | added | Salvo Tringali | Right, right. One question that comes to mind could be: Which of the "classical upper densities" is extremal (in $\mathscr U$)? For instance, is the upper logarithmic density extremal? | |
| Apr 8, 2016 at 16:06 | comment | added | Martin Sleziak | @SalvoTringali Maybe I misunderstood your last comment, but I will remind you that KM does not say that the set is convex hull of its extreme points but that it is closure of this convex hull. So it is possible that we do not get all upper densities by taking all convex combinations of the extremal ones. (But it would still be a dense subset.) | |
| Apr 8, 2016 at 14:48 | comment | added | Martin Sleziak | Edited. I hope I did not miss something in the above argument and typos and terminology will be the only problems. | |
| Apr 8, 2016 at 14:45 | history | edited | Martin Sleziak | CC BY-SA 3.0 |
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| Apr 8, 2016 at 14:41 | comment | added | Salvo Tringali | A minor detail: I think you mean "weakly additive upper density" wherever your write "weakly additive measure", don't you? | |
| Apr 8, 2016 at 13:08 | vote | accept | Salvo Tringali | ||
| Apr 8, 2016 at 12:09 | history | answered | Martin Sleziak | CC BY-SA 3.0 |