## Contact Info

Pure MathematicsUniversity of Waterloo

200 University Avenue West

Waterloo, Ontario, Canada

N2L 3G1

Departmental office: MC 5304

Phone: 519 888 4567 x33484

Fax: 519 725 0160

Email: puremath@uwaterloo.ca

Monday, February 24, 2020 — 4:00 PM EST

**Zhouli Xu, MIT**

"In and around stable homotopy groups of spheres"

Tuesday, February 18, 2020 — 1:30 PM EST

**Angelos Koutsianas, University of British Columbia**

"Solving generalized Fermat equations with Frey hyperelliptic curves"

In this talk, I will talk about Darmon's program and the resolution of the generalized Fermat equation of signature (p,p,5) using Frey hyperelliptic curves. This is joint work with Imin Chen (Simon Fraser University).

MC 5417

Tuesday, February 18, 2020 — 11:00 AM EST

**Spiro Karigiannis, Department of Pure Mathematics, University of Waterloo**

"Bryant-Salamon G2 manifolds and coassociative fibrations"

Tuesday, February 18, 2020 — 10:00 AM EST

**Patrick Naylor, Department of Pure Mathematics, University of Waterloo**

"The category of cobordisms (Part III)"

We specialize to the 2-cobordism category, and work towards developing a set of generators and relations.

MC 5417

Friday, February 14, 2020 — 3:30 PM EST

**Kathryn Hare, Department of Pure Mathematics, University of Waterloo**

"The size of complementary sets"

Wednesday, February 12, 2020 — 2:30 PM EST

**Brett Nasserden, Department of Pure Mathematics, University of Waterloo**

"An introduction to the Laplacian operator on a metrized graph"

In this presentation we shall attempt to give a self contained introduction to finite metrized graphs. Following this introduction we shall discuss how to define a Laplacian operator on a finite metrized graph and discuss its basic properties.

MC 5403

Tuesday, February 11, 2020 — 1:30 PM EST

**Jerry Wang, Department of Pure Mathematics, University of Waterloo**

"Density of polynomials with squarefree discriminant II"

In this talk, we will discuss the squarefree sieve for discriminants of arbitrary polynomials. We will find that there are striking differences between odd and even degree polynomials, where additional techniques of counting on varieties will be required for the latter. This is joint work with Manjul Bhargava and Arul Shankar.

MC 5417

Tuesday, February 11, 2020 — 10:30 AM EST

**Jinhe Ye, University of Notre Dame**

"A model theoretic adic space"

Tuesday, February 11, 2020 — 10:00 AM EST

**Patrick Naylor, Department of Pure Mathematics, University of Waterloo**

"The category of cobordisms (Part II)"

We will continue to discuss the category of cobordisms, along with more examples.

MC 5417

Monday, February 10, 2020 — 4:00 PM EST

**Marco Gualtieri, University of Toronto **

"From generalized Kahler geometry to noncommutative algebra"

Friday, February 7, 2020 — 3:30 PM EST

**Adam Humeniuk, Department of Pure Mathematics, University of Waterloo**

"On C*-Envelopes of Semicrossed Products"

Friday, February 7, 2020 — 10:00 AM EST

**Note: Special time and room**

**Sergey Cherkis, University of Arizona**

"Compactification of Monopole Moduli Spaces"

Monopole's dynamic is well approximated by the geodesic motion on its moduli space. This provided the initial motivation for studying monopole moduli spaces. Recently, these spaces acquired new significance as they deliver numerous examples of gravitational instantons and of spaces of vacua of quantum field theories. In this light the L2 cohomology of these spaces is particularly important.

Thursday, February 6, 2020 — 4:30 PM EST

**Benjamin Anderson-Sackaney, Department of Pure Mathematics, University of Waterloo**

"Honeycombs and the Horn Problem"

Wednesday, February 5, 2020 — 2:30 PM EST

"Potential Theory for Metric Trees"

We discuss potential theory for general metric trees and explain how to apply it in our study of the valuative tree.

MC 5403

Tuesday, February 4, 2020 — 1:30 PM EST

"The density of power-free values of polynomials"

In this talk we show that any polynomial $F(x_1, \cdots, x_n)$ with integer coefficients and degree $d \geq 3$ and which satisfy basic necessary conditions take on the expected density of $k$-free values, provided that $k \geq \min\{d-1, 3d/4\}$. This generalizes results of Hooley and Browning, who showed the same result with $n = 1$. This is joint work with K. Lapkova.

Tuesday, February 4, 2020 — 11:00 AM EST

"Vector Bundles on Non-Kähler Elliptic Fibre Bundles"

In this talk we will discuss non-Kähler complex surfaces which occur as elliptic fibre bundles, and some invariants of holomorphic vector bundles on these surfaces.

Tuesday, February 4, 2020 — 10:00 AM EST

**Patrick Naylor, Department of Pure Mathematics, University of Waterloo **

“The category of cobordisms (Part II)”

We will continue to discuss the category of cobordisms, along with more examples.

MC 5417

Friday, January 31, 2020 — 3:30 PM EST

**Guy Salomon, Department of Pure Mathematics, University of Waterloo**

"The mysterious connection between proximal actions and Poisson boundaries"

Friday, January 31, 2020 — 2:35 PM EST

**Andrew Staal, Department of Pure Mathematics, University of Waterloo**

"Ubiquity of Smooth Hilbert Schemes"

Tuesday, January 28, 2020 — 11:00 AM EST

**Ragini Singhal, Department of Pure Mathematics, University of Waterloo**

"Deformation theory of nearly G_2 manifolds - 2"

In this talk we will prove some results about the cohomology of nearly G_2 manifolds which we will use to define the space of first order deformation of a nearly G_2 structure. We will then prove that it is an eigenspace of the Laplace operator. Time permitting we will also define the second order deformations and their formulation. This talk is based on a joint work in progress with Shubham Dwivedi.

MC 5413

Tuesday, January 28, 2020 — 10:30 AM EST

**Rahim Moosa, Department of Pure Mathematics, University of Waterloo**

"NIP XI"

We continue section 3.4 of Simon's Guide to NIP theories.

M3 3103

Tuesday, January 28, 2020 — 10:00 AM EST

**Partrick Naylor, Department of Pure Mathematics, University of Waterloo**

"The category of cobordisms"

In this talk, we’ll discuss how n-manifolds considered up to cobordism form a category, as well as some of the subtleties involved.

MC 5417

Monday, January 27, 2020 — 11:30 AM EST

**Brett Nasserden, Department of Pure Mathematics, University of Waterloo**

"Introduction to Arakelov Theory"

I will introduce the basic concepts of Arakelov theory with a focus on arithmetic surfaces.

MC 5417

Friday, January 24, 2020 — 2:30 PM EST

**Xi Sisi Shen, Northwestern University**

"Estimates for metrics of constant Chern scalar curvature"

We discuss the existence problem of constant Chern scalar curvature metrics on a compact complex manifold. We prove a priori estimates for these metrics conditional on an upper bound on the entropy, extending a recent result by Chen-Cheng in the K\"ahler setting.

MC 5403

Wednesday, January 22, 2020 — 3:30 PM EST

**Alex Chirvasitu, University of Buffalo**

"Loosely embeddable metric spaces"

Embedding finite metric spaces isometrically into Hilbert spaces has elicited some interest outside of pure mathematics due to applications to fields like computer vision, machine learning, the structure of networks and other such areas.

University of Waterloo

200 University Avenue West

Waterloo, Ontario, Canada

N2L 3G1

Departmental office: MC 5304

Phone: 519 888 4567 x33484

Fax: 519 725 0160

Email: puremath@uwaterloo.ca

University of Waterloo

University of Waterloo

43.471468

-80.544205

200 University Avenue West

Waterloo,
ON,
Canada
N2L 3G1