Friday, October 25, 20132:00 pmCUNY Logic WorkshopGC 6417

# Automorphism Groups of Countable, Recursively Saturated Models of Peano Arithmetic

## Jim Schmerl

### University of Connecticut

It is still unknown whether there are nonisomorphic countable recursively saturated models M and N whose automorphism groups Aut(M) and Aut(N) are isomorphic. I will discuss what has happened over the last 20 years towards showing that such models do not exist, including some very recent results.