4 papers · 1 filter
Ramsey Theory and Bounding in Arithmetic
Peter Cholak
We explore the relation between various versions of Ramsey theorem and bounding schemes in model of a fragment of arithmetic . Our goal is to recast, in a different framew…
The finite big Ramsey degrees of Henson graphs are provable in
Peter Cholak, Natasha Dobrinen, Henry Towsner
Let denote a computable copy of the -clique free universal homogeneous Henson graph, denote a finite subgraph of , and deno…
The Henson graphs: colorings and codings
Peter Cholak, Natasha Dobrinen, Charlie McCoy
By recent work of \citet{DobrinenICM} and \citet{Balko7} we know that every finite in the Henson graph (the universal ultrahomogeneous -clique free gr…
Low computably enumerable sets have hyperhypersimple supersets
Peter Cholak, Rodney Downey, Noam Greenberg
A longstanding question is to characterize the lattice of supersets (modulo finite sets), , of a low computably enumerable (c.e.) set. The conjecture is that…