Indira Chatterji, Ohio State University

Abstract: Median spaces are geodesic metric spaces where any triple of points has a unique median point, that is a point lying simultaneously on 3 geodesics between those points. I will give examples of median spaces, known results concerning those and describe a few properties of groups admitting a proper action on a median space. This talk is accessible to non-specialists, and is on joint work with C. Drutu and F. Haglund.