University of Regina

We will discuss the link between Hochschild cohomology and deformations of an algebra A. We will see that the Hochschild cochains of A can be endowed with a differential graded (DG) Lie algebra structure. The Maurer-Cartan equation describes the...

An Azumaya algebra is something that is "locally" isomorphic to a matrix algebra. By varying the sense of "locally", we arrive at different incarnations of the concept. The motivating example is that of central simple algebras over a field. In this...

This is joint work with Uriya First. Azumaya algebras are objects that are locally isomorphic to matrix algebras—over a topological space X, they are bundles of matrix algebras. If the base space X is endowed with a self-map of order 2 (which may be...

What does a random permutation group look like? This talk will start with a brief survey of how we might go about counting subgroups of the symmetric group Sn, and talk about what is known about “most” subgroups. To tackle the general problem, it...

The action of the automorphisms of a formal group on its deformation space is crucial to understanding periodic families in the homotopy groups of spheres and the unsolved Hecke orbit conjecture for unitary Shimura varieties. We can explicitly pin...

The theme of this lecture is the dichotomy between amenability and non-amenability, both in operator algebras and ergodic theory. I will review the fundamental classification results for amenable von Neumann algebras due to Connes and Haagerup. Then...

Triangulated categories were introduced to capture some of the extra structure present in the derived category of a ring and the stable homotopy category, and today they are present wherever homological algebra plays a central role. In the case of...

We will present the "method of killing homotopy groups" due to Cartan and Serre in the 1950s, a method to compute some homotopy groups of spheres. The method relies on the Hurewicz theorem and the Serre spectral sequence of the fibration that kills...

Periods are numbers that arise as integrals of rational functions with coefficients in Q over sets that are cut out by polynomial inequalities with coefficients in Q. More conceptually, periods are numbers that arise from the natural isomorphism...