Descriptive chromatic numbers of locally finite and everywhere two-ended graphs

Abstract

We construct Borel graphs which settle several questions in descriptive graph combinatorics. These include “Can the Baire measurable chromatic number of a locally finite Borel graph exceed the usual chromatic number by more than one?” and “Can marked groups with isomorphic Cayley graphs have Borel chromatic numbers for their shift graphs which differ by more than one?” We also provide a new bound for Borel chromatic numbers of graphs whose connected components all have two ends.