Colors of the Pseudotree
arXiv:2503.18727
Abstract
We investigate big Ramsey degrees of finite substructures of the universal countable homogeneous meet-tree and its binary variant. We prove that structures containing antichains have infinite big Ramsey degrees, and the big Ramsey degree of a 2-element chain is at least 8 and 7 for the binary variant. We deduce that the generic C-relation does not have finite big Ramsey degrees.
Accepted as Eurocomb'25 extended abstract with hard page limit; compromises in presentation were made