# Poster

Friday, November 18, 201612:30 pmModel theory seminarGC 6417

# First order expansions of the ordered group of real numbers

## Erik Walsberg

### University of Illinois Urbana-Champaign

We discuss (part of) the classification of first order expansions of $(\mathbb{R},<,+)$ according to the geometry and topology of their definable sets. Joint work with Philipp Hieronymi, following work of Hieronymi, Fornasiero, Miller, and Tychonievich.