When

Start: 02/24/2010 - 4:15pm

End : 02/24/2010 - 5:15pm

End : 02/24/2010 - 5:15pm

Category

Colloquium

Speaker

Erica Flapan, Pomona College

Abstract

Chemists have defined the point group of a molecule as the group of rigid symmetries of its molecular graph in R^{3}. While this group is useful for analyzing the symmetries of rigid molecules, a molecular structure which is flexible or can rotate around one or more bonds may have symmetries which are not induced by a rigid motion and hence are not included in the point group. To study the symmetries of such molecules, we define the topological symmetry group of a graph embedded in R^{3} to be the subgroup of the automorphism group of the abstract graph that is induced by homeomorphisms of R^{3}. This group gives us a way to understand not only the symmetries of non-rigid molecular graphs, but the symmetries of any graph embedded in R^{3}. The study of such symmetries is a natural extension of the study of symmetries of knots. In this talk we will present a survey of results about the topological symmetry group and how it can play a role in analyzing the symmetries of non-rigid molecules.

Where

Beckman B126, Harvey Mudd College

Misc. Information

Coffee & Cookies at 3:45 pm in Olin B161 Harvey Mudd College

The dinner will be hosted by Professor Sam Nelson

If interested in attending, please call ext 78979