Simplicity of the automorphism groups of order and tournament expansions of homogeneous structures

Filippo Calderoni, Aleksandra Kwiatkowska, Katrin Tent

Abstract

We define the notions of a free fusion of structures and a weakly stationary independence relation and use them to prove simplicity for the automorphism groups of order and tournament expansions of homogeneous structures like the rational bounded Urysohn space, the random graph, and the random poset.