University of Regina

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...

Topological quantum field theories (TQFTs) are one of several mathematical approaches to quantum field theory in physics. They were introduced by Atiyah in the 1980s. The cobordism hypothesis, proposed by Baez and Dolan in the 1990s, is a statement...

The Cobordism Hypothesis, as proposed by Baez and Dolan in 1995, provides a classification of n-extended Topological Quantum Field Theories (TQFTs). A n-extended TQFT is a symmetric monoidal n-functor from the n-category of cobordisms to an arbitrary...

Topological K-theory is an assignment of algebraic data to a topological space. It is a homotopy invariant and satisfies the Eilenberg-Steenrod axioms for a generalized cohomology theory. In this talk I give a rapid introduction to vector bundles...

The classification of 2-dimensional TQFTs was obtained by cutting up surfaces into disks, cylinders, and pairs of pants. In higher dimension, such a decomposition of n-manifolds is not available. We need to cut up manifolds not only along codimension...