Mathematics Colloquium Symmetries, Outer Space, & the Outer Automorphism Group of the Free Group
Catherine Pfaff Department of Mathematics UCSB Friday, February 24, 2017 4:10 – 5 p.m. Building 53 Room 201 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.
About the speaker: Catherine Pfaff is the Ky Fan Visiting Assistant Professor at UCSB. She fell in love with math as an undergraduate at the University of Chicago and went on to earn her Ph.D. from Rutgers University, New Brunswick. Before moving to Santa Barbara she spent three years as a postdoc in Europe at the CRM in Barcelona, Universitat d’Aix Marseille, & the University of Bielefeld. Her research is in the exciting and active field of geometric group theory.