Uniform homogeneity
Speaker:
Wieslaw Kubis, Institute of Mathematics, Czech Academy of Sciences
Date and Time:
Thursday, May 16, 2019 - 2:00pm to 2:45pm
Location:
Fields Institute, Room 230
Abstract:
A mathematical structure $M$ is homogeneous if every isomorphism between its ``small'' (typically: finite, or finitely generated) substructures extends to an automorphism of $M$. Fraisse theory provides tools for constructing many examples of homogeneous structures. We will discuss a stronger notion, called uniform homogeneity, which leads to embeddings of the automorphism groups of small substructures of $M$ into the automorphism group of $M$. As it happens, typical homogeneous structures are uniformly homogeneous. We shall present examples of homogeneous structures, showing that uniform homogeneity is significantly stronger than homogeneity.
The talk is based on a joint work with S. Shelah (\texttt{https://arxiv.org/abs/1811.09650}).