## Contact Info

Pure MathematicsUniversity of Waterloo

200 University Avenue West

Waterloo, Ontario, Canada

N2L 3G1

Departmental office: MC 5304

Phone: 519 888 4567 x43484

Fax: 519 725 0160

Email: puremath@uwaterloo.ca

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.

Wednesday, January 22, 2020 — 2:30 PM EST

**Matt Satriano, Department of Pure Mathematics, University of Waterloo**

"Introduction to Valuative Trees and its connection with dynamics"

We will review where we left off last term, highlighting the main results concerning valuative trees and the role they play in Junyi Xie's proof of the Medevdev-Scanlon Conjecture for the affine plane.

MC 5403

Tuesday, January 21, 2020 — 2:00 PM EST

**Luke MacLean, Department of Pure Mathematics, University of Waterloo**

"Reverse Mathematics"

Different forms of Ramsey's Theorem will be discussed with a focus on their reverse mathematical strength. Tools from computability theory such as PA degrees will be used.

MC 5413

Tuesday, January 21, 2020 — 1:30 PM EST

**Anup Dixit, Queen's University**

"On Ihara's conjecture and the localized Erdos-Kac theorem"

Tuesday, January 21, 2020 — 11:00 AM EST

**Aidan Patterson, Department of Pure Mathematics, University of Waterloo**

"Thimm’s Trick and the Gelfand-Zeitlin System"

Tuesday, January 21, 2020 — 10:30 AM EST

**Christopher Hawthorne, Department of Pure Mathematics, University of Waterloo**

"NIP X"

We continue section 3.3 of Simon's Guide to NIP theories.

M3 3103

Tuesday, January 21, 2020 — 10:00 AM EST

**Andrej Vukovic, Department of Pure Mathematics, University of Waterloo**

This week, we continue to study the cobordism and introduce the definition of Topological quantum field theories.

MC 5417

Monday, January 20, 2020 — 4:00 PM EST

**Igor Shparlinski, University of New South Wales**

"Integers of prescribed arithmetic structure in residue classes"

Tuesday, January 14, 2020 — 1:30 PM EST

**Dimitris Koukoulopoulos, Université de Montréal**

"On the Duffin-Schaeffer conjecture"

Tuesday, January 14, 2020 — 11:00 AM EST

**Shubham Dwivedi, Department of Pure Mathematics, University of Waterloo**

"Deformation theory of nearly G_2 manifolds"

I will start by describing nearly G_2 manifolds and the infinitesimal deformations of nearly G_2 structures. I will describe the results of Alexandrov and Semmelmann on the deformations of nearly G_2 structures and will give a different proof of their result by using a modified Dirac operator.

MC 5413

Tuesday, January 14, 2020 — 10:30 AM EST

**Wilson Poulter, Department of Pure Mathematics, University of Waterloo**

"NIP IX, take 2"

We continue section 3.2 of Simon's Guide to NIP theories.

M3 3103

Tuesday, January 14, 2020 — 10:00 AM EST

**Andrej Vukovic, Department of Pure Mathematics, University of Waterloo**

This week, we continue our study of topological quantum field theories by discussing Morse theory and introducing the notion of cobordism.

MC 5417

Monday, January 13, 2020 — 4:00 PM EST

**Dimitris Koukoulopoulos, Université de Montréal**

"Approximating reals by rationals"

Tuesday, January 7, 2020 — 11:00 AM EST

There will be an organizational meeting of the Geometry Working Seminar on Tuesday, January 7, 2020, at 11:00 am in MC 5413.

Tuesday, January 7, 2020 — 10:00 AM EST

**Hongdi Huang, Department of Pure Mathematics, University of Waterloo**

In this very kick-off talk, we will go through section 1.1. We aim to recall/learn some basic notions of manifolds with boundary and orientations, and Morse functions in the section. We also introduce the slightly nonstandard notion of in-boundary and out-boundary, which is particularly convenient for the treatment of cobordisms. Besides, we will take about the outline and the goals of this seminar.

MC 5417

University of Waterloo

200 University Avenue West

Waterloo, Ontario, Canada

N2L 3G1

Departmental office: MC 5304

Phone: 519 888 4567 x43484

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

The University of Waterloo acknowledges that much of our work takes place on the traditional territory of the Neutral, Anishinaabeg and Haudenosaunee peoples. Our main campus is situated on the Haldimand Tract, the land granted to the Six Nations that includes six miles on each side of the Grand River. Our active work toward reconciliation takes place across our campuses through research, learning, teaching, and community building, and is centralized within our Indigenous Initiatives Office.