Rob Sullivan

collaborators

3 papers

math.LO2026

An unusual example of a universal automorphism group

Rob Sullivan, Jeroen Winkel

Let $M$ be a FraÃ¯ssÃ© structure (a countably infinite ultrahomogeneous structure). We refer to the class of structures embeddable in $M$ as the $I ¨ $ -age of $M$ . We consider the fo…

math.LO2026

Determining the normal subgroups of the automorphism groups of ultrahomogeneous structures via stabilisers

Thomas Bernert, Rob Sullivan, Jeroen Winkel +1

We show the simplicity of the automorphism groups of the generic $n$ -hypertournament and the semigeneric tournament, and determine the normal subgroups of the automorphism groups o…

math.LO2025

Flows of linear orders on sparse graphs

Rob Sullivan

We consider the topological dynamics of the automorphism group of a particular sparse graph M_1 resulting from an ab initio Hrushovski construction. We show that minimal subflows o…