Dear all,
This week there is no noon lecture.
The last noon lecture of the semester will be on Tuesday, 7 June, and will be given by Jindrich Zapletal, the talk details are given below. Please be aware of the unusual day, time and meeting room.
Best regards, Misha.
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Coloring graphs on Euclidean spaces Jindrich Zapletal University of Florida / Czech Academy of Sciences June 7, 2022, 15:00 in S5
Abstract For n>0, let Gn be the graph connecting points in Rn of rational Euclidean distance. In ZFC, these graphs all have countable chromatic number. I proved that for every n>0, it is consistent with choiceless set theory that Gn has countable chromatic number while Gn+1 does not, showing that the coloring problem grows in difficulty with n. The proof depends on certain finite combinatorial features of Rn, and the talk will concentrate on these.
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