# Descartes, Euler, Gauss: From surfaces to integers. Hirzebruch Lecture 2017 by Werner Ballmann

Speaker: Werner Ballmann
Affiliation: Max Planck Institute for Mathematics, Bonn
Date: Tue, 2017-11-13 18:30 - 19:30
Location: University Club Bonn
Homepage: MPIM

Geometric quantities of a surface, like distance, angle, or area, change when the surface is deformed. Euler discovered a quantity, the Euler characteristic, which remains unchanged. The formula of Gauss-Bonnet, a landmark result of mathematics, relates Euler characteristic with geometry. In the talk, I will present ideas of Descartes, Euler, and Gauss related to this formula.