Friday, October 4, 201312:30 pmModel theory seminarGC6417

# Real closures of $omega_1$-like models of PA

## David Marker

### University of Illinois at Chicago

In an earlier seminar I showed that assuming diamond we can build many $omega_1$-like models of PA with the same standard system but non-isomorphic real closures. In this lecture I will show how to do this without diamond. This is joint work with Jim Schmerl and Charlie Steinhorn.

Professor Marker holds the position of LAS Distinguished Professor in the Department of Mathematics, Statistics, and Computer Science at the University of Illinois at Chicago. He conducts research in model theory and it applications, particularly in applications to real algebraic geometry and real analytic geometry, exponentiation and differential algebra. His excellent textbook Model Theory: an Introduction is widely studied.