Title: Homotopy Groups of First-Order Theories
Abstract: This summer Campion and Ye released a paper calculating the second homotopy group on the classifying space of the first-order theory of dense cyclic orders with two points. This expounds on their earlier work on classifying spaces for theories and their model-theoretic properties. Campion and Ye’s construction is a surprising application of Quillen’s Theorem A.
I will outline Campion and Ye’s work, and I will show how it fits into a network of papers building a bridge between first-order logic and topology.
