Department of Mathematics
What initial segments do automorphisms fix?
Amir Togha
George Washington University
An automorphism of a model M is simply a permutation of M's universe that preserves the structure of M. In this talk we discuss certain models of Arithmetic and Set Theory and their automorphisms. The notion of "initial segment" will be introduced for these models and the properties of the largest initial segments that are fixed by automorphisms will be investigated. The goal is to give a characterization of such initial segments for sufficiently rich models of Set Theory.
All interested persons are welcome.