4 papers
Topological weak containment
Riley Thornton
We build on work of Elek and Zucker and develop a topological analogue of the theory of weak containment. We show that definitions in terms of local patterns, containment in ultra(…
Open Problems in Computability Theory and Descriptive Set Theory
George Barmpalias, Nikolay Bazhenov, Chi Tat Chong +11
These open problems were presented in the Problem Sessions held during the Tianyuan Workshop on Computability Theory and Descriptive Set Theory, June 16-20, 2025. The problems are…
Limits of sparse hypergraphs
Riley Thornton
We generalize ultraproducts and local-global limits of graphs to hypergraphs and other structures. We show that the local statistics of an ultraproduct of a sequence of hypergraphs…
Factor maps for automorphism groups via Cayley diagrams
Riley Thornton
We leverage a correspondence between group actions and edge-labelled graphs in two ways. First, we give a unified presentation of several folklore results connecting weak containme…