Geometry and Topology

Speaker: Marcy Robertson (Western)

"Operads, multicategories, and higher dimensional deformations"

Time: 15:30

Room: MC 107

Operads, and the more general multicategories, are combinatorial devices originally used in algebraic topology as a ``bookkeeping'' devices that described the internal operations of iterated loop spaces. The basic idea of an operad, however, is quite flexible and can be adapted to problems in algebra, mathematical physics, and computer science. The goal of this talk is to give a quick introduction to the Grothendieck-Teichm\"{u}ller group, as introduced by Drinfeld and Ihara, describe some of the conjectures relating this group to quantized deformations, and explain how this conjecture is being understood through the machinery of operads (up to homotopy).

Colloquium

Speaker: Boris Khesin (University of Toronto)

"Symplectic fluids and point vortices"

Time: 15:30

Room: MC 107

We describe the motion of symplectic fluids as an Euler-Arnold equation for the group of symplectic diffeomorphisms. We relate it to the Lagrangian study of symplectic fluids by D.Ebin, describe a symplectic analog of vorticity and the finite-dimensional Hamiltonian systems of symplectic point vortices.

Noncommutative Geometry

Speaker: Jason Haradyn (Western)

"Ricci Flow in Differential and Noncommutative Geometry (2)"

Time: 10:30

Room: MC 108

Studying the Ricci flow of a smooth, closed manifold M equipped with a Riemannian metric g involves the process of allowing the metric g to evolve over time under the PDE g_{t} = -2Ric(g). Ricci flow was, in fact, the main tool used by Perelman to prove the Poincare conjecture. The purpose of this talk will be to discuss what is Ricci flow, to present where it comes from and to provide examples of Ricci flow of certain manifolds. Our discussion will then lead into an analysis of a paper written by Bhuyain and Marcolli, who constructed a version of Ricci flow for noncommutative two-tori. The Ricci flow is a fundamental tool used to understand the geometry and topology of manifolds, and understanding it well will help us understand how we can classify other noncommutative spaces such as noncommutative tori in higher dimensions.

Algebra Seminar

Speaker: Ali Moatadelro (Western)

"Spectral geometry of noncommutative two torus "

Time: 14:30

Room: MC 107

Recently an analogue of the Gauss-Bonnet theorem has been proved by Connes-Tretkoff and Fathizadeh-Khalkhali for noncommutative two torus. The idea is based on the direct computation of the value at origin of the zeta function associated to the corresponding Laplacian. In this talk we will briefly discuss the above theorem and explain a related problem.