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Colloquium with Catherine Pfaff

Date: December 4, 2018

Time: 1:30PM

Location: Rockefeller Hall 300

Title: Symmetries, Outer Space, & the Outer Automorphism Group of the Free Group

Abstract: The symmetries of a polygon form a group. This group acts on the polygon by rotating it and flipping it. This basic idea of studying a group as symmetries of an object extends far beyond polygons. My favorite group is the outer automorphism group of the free group. Through a myriad of colorful pictures I will introduce this group and the object, Culler-Vogtmann Outer Space, that it acts on. No advanced mathematical knowledge will be assumed & of course we will also play with doughnuts!