Borel chromatic number of closed graphs

Dominique Lecomte (1) , Miroslav Zeleny (2)

1 IMJ - Institut de Mathématiques de Jussieu
2 Department of Mathematical Analysis [Prague]

We construct, for each countable ordinal $\xi$, a closed graph with Borel chromatic number two and Baire class $\xi$ chromatic number $\aleph_0$.

Mots clés: Borel chromatic number; Borel class; coloring

Domaines: Logique [math.LO]; Topologie générale [math.GN]

Dominique Lecomte, Miroslav Zeleny. Borel chromatic number of closed graphs. 2014. ⟨hal-01016210v2⟩