Choquet simplexes whose set of extreme points is K-analytic
Talagrand, Michel
Annales de l'Institut Fourier, Tome 35 (1985), p. 195-206 / Harvested from Numdam

On construit un simplexe de Choquet dont l’ensemble des points extrémaux T est 𝒦-analytique, mais n’est pas 𝒦-Borélien. L’ensemble T est un K σδ dans sa compactification de Stone-Cech. C’est donc un exemple d’ensemble K σδ qui n’est pas absolu.

We construct a Choquet simplex K whose set of extreme points T is 𝒦-analytic, but is not a 𝒦-Borel set. The set T has the surprising property of being a K σδ set in its Stone-Cech compactification. It is hence an example of a K σδ set that is not absolute.

@article{AIF_1985__35_3_195_0,
     author = {Talagrand, Michel},
     title = {Choquet simplexes whose set of extreme points is $K$-analytic},
     journal = {Annales de l'Institut Fourier},
     volume = {35},
     year = {1985},
     pages = {195-206},
     doi = {10.5802/aif.1024},
     mrnumber = {87a:46022},
     zbl = {0564.46008},
     language = {en},
     url = {http://dml.mathdoc.fr/item/AIF_1985__35_3_195_0}
}
Talagrand, Michel. Choquet simplexes whose set of extreme points is $K$-analytic. Annales de l'Institut Fourier, Tome 35 (1985) pp. 195-206. doi : 10.5802/aif.1024. http://gdmltest.u-ga.fr/item/AIF_1985__35_3_195_0/

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