This file can be used to add scheduled events to your calendar, however every program is unique. Below you will find what information is available, but if nothing else works try creating a new calendar in your program and using
http://math.colorado.edu/seminars/ics/homo.ics
as the source.
Thunderbird
Tue, Oct. 13 1:30pm (Math 3…
Theo Johnson-Freyd (Perimeter Institute for Theoretical Physics and Dalhousie University)
X
Abstract: Kitaev has argued that the spaces of n-dimensional invertible phases of matter, as n varies, fit together into the structure of an Omega-spectrum. It follows that each n-dimensional phase determines a (possibly trivial) character on the nth stable homotopy group of spheres. I will present an enforced-gaplessness theorem (conditional on some reasonable semisimplicity assumptions about the category of topological phases of matter): if this character is nontrivial, and not one of the six nontrivial Kervaire invariants, then the invertible phase is a topological insulator: a material all of whose boundary conditions have gapless conducting modes. This is joint work in progress with David Reutter.
With six exceptions, nontrivial characters of spheres do not admit gappable boundary conditions Sponsored by the Meyer Fund
Tue, Nov. 10 1:30pm (Math 3…
Mike Hill (University of Minnesota)
X
In the last decade, we have seen tremendous progress in equivariant algebra, with significant classical algebraic geometry theorems being reproved in the equivariant context. One thing that makes the story trickier is that here we have lots of generalizations of an ordinary commutative ring: the incomplete Tambara functors. The additional data here makes the underlying algebra significantly harder to understand. In this talk, I will focus on a piece of that algebra: what do we mean by a module? There are several different answers to this question, and I will show how they fit together.
Modules in equivariant algebra Sponsored by the Meyer Fund
With six exceptions, nontrivial characters of spheres do not admit gappable boundary conditions