Friday, March 8, 201312:00 amModel theory seminarGC 6417

# On strength of weakness

## Roman Kossak

### The City University of New York

I will explain why countable models of PA which are just recursively saturated do not have maximal automorphisms. If time permits I will also show why recursive saturation implies standard system saturation for models of rich theories.

Roman Kossak is professor of mathematics at The City University of New York, at Bronx Community College and also at the CUNY Graduate Center. He conducts research in mathematical logic, especially in model theory of Peano Arithmetic.