Events

Ian Hambleton, McMaster University

"Euler Characteristics and 4-manifolds"

The topology and total curvature of a Riemann surface is determined by a single integer, the Euler characteristic (Leonhard Euler, 1707-1783). In dimension four and higher, the Euler characteristic gives an interesting invariant for finitely presented groups. The talk will survey some recent joint work with Alejandro Adem on this theme.

MC 5501

Jeremy Champagne, Department of Pure Mathematics, University of Waterloo

"Geometry of numbers as a tool for Diophantine approximation"

Anybody who has taken a course on algebraic number theory, has probably seen Minkowski's convex body theorem as a mean to prove the finiteness of class groups. However, less people know about Minkowski's second convex body theorem, which gives much more insight into this problem of finding integer points with certain properties.

Elliot Kaplan, McMaster University

"Hilbert polynomials for finitary matroids"

Spiro Karigiannis, Department of Pure Mathematics, University of Waterloo

"Nearly Kahler 6-manifolds have SU(3)-structures"

David McKinnon, Department of Pure Mathematics, University of Waterloo

"Gaussian integers and gcds"

Changho Han, Department of Pure Mathematics, University of Waterloo

"A Brief Introduction to the General MMP Part 2"

Continuing from where we left off last time, I will discuss singularities of the MMP. Then, I will give a brief explanation of how the higher-dimensional MMP works; note that there will be some key differences from the surface case, including flips.

This seminar will be held jointly online and in person:

Leo Jimenez, Department of Pure Mathematics, University of Waterloo

"Not pfaffian, Part II"

James Freitag has shown that the j-function is not Pfaffian using the model theory of differentially closed fields. We will work though his paper, entitled "Not pfaffian".

MC 5417

Michael Albanese, Department of Pure Mathematics, University of Waterloo

"Spin^h and further generalisations of spin"

Luke MacLean, Department of Pure Mathematics, University of Waterloo

"Effectively closed sets - Part IV"

An effectively closed set (or $\Pi^0_1$ class) in Baire space $\omega^\omega$ is the set $[T]$ of infinite branches through a computable tree $T$. This semester in the computability seminar, we will be studying $\Pi^0_1$ classes from Cenzer \& Remmel's textbook. This week we will begin on chapter 3.

MC 5403

Robert Martin, University of Manitoba

"Non-commutative measure theory"