# What is ... a **hyperreal number**?

This page hosts information on Ugur Dogan's talk "What is ... a

**hyperreal number**?" at the

"What is ...?" seminar. The talk will take place on Friday, October 25, 4:00pm at HU, RUD 25 1.023.

## Abstract

The set of Hyperreal Numbers is a field which contains R (real numbers) and some "infinitesimal" and "infinite" numbers. It will be constructed using Model Theory, so some basic facts and theorems in Model Theory will also be mentioned, such as Łoś's Theorem and Compactness of First Order Logic (and some applications if time permits).

## Comments