## 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

Visit our COVID-19 information website to learn how Warriors protect Warriors.

Please note: The University of Waterloo is closed for all events until further notice.

Thursday, December 3, 2020 — 4:00 PM EST

**Mani Thamizhazhagan, Department of Pure Mathematics, University of Waterloo**

"On the interplay of harmonic analysis, combinatorics, additive number theory and ergodic theory"

Thursday, December 3, 2020 — 1:00 PM EST

**Elana Kalashnikov, Harvard University**

"Quiver flag varieties and mirror symmetry"

Tuesday, December 1, 2020 — 1:00 PM EST

**Junliang Shen, MIT**

"The P=W conjecture and hyper-Kähler geometry"

The P=W conjecture by de Cataldo, Hausel, and Migliorini suggests a surprising connection between the topology of Hitchin systems and Hodge theory of character varieties. In this talk, we will focus on interactions between topology of Lagrangian fibrations and Hodge theory in general hyper-Kaehler geometries. Such connections shed new light on both the P=W conjecture for Hitchin systems and the Lagrangian base conjecture for compact hyper-Kähler manifolds.

Monday, November 30, 2020 — 4:00 PM EST

**Jonathan Zhu, Princeton**

"Mean curvature flow and explicit Łojasiewicz inequalities"

Friday, November 27, 2020 — 2:30 PM EST

**Brady Ali Medina, Department of Pure Mathematics, University of Waterloo**

"A different way to generalize the Weierstrass semigroup"

Friday, November 27, 2020 — 1:00 PM EST

**Michael Brannan, Texas A&M University**

"Quantum symmetries of graphs"

Thursday, November 26, 2020 — 4:00 PM EST

**Caleb Suan, Department of Pure Mathematics, University of Waterloo**

"Intro to Knots and Knot Invariants"

Thursday, November 26, 2020 — 1:00 PM EST

**Lei Alice Chen, California Institute of Technology**

"Actions of Homeo and Diffeo groups on manifolds"

In this talk, I discuss the general question of how to obstruct and construct group actions on manifolds. I will focus on large groups like Homeo(M) and Diff(M) about how they can act on another manifold N. The main result is an orbit classification theorem, which fully classifies possible orbits. I will also talk about some low dimensional applications and open questions. This is a joint work with Kathryn Mann.

Wednesday, November 25, 2020 — 2:30 PM EST

**Yifeng Huang, University of Michigan - Ann Arbor**

"A generating function for counting mutually annihilating matrices over a finite field"

Monday, November 23, 2020 — 4:00 PM EST

**Gigliola Staffilani, MIT**

"The many faces of dispersive equations"

Friday, November 20, 2020 — 2:30 PM EST

**Ákos Nagy, University of California Santa Barbara**

"The asymptotic geometry of G_2-monopoles"

Wednesday, November 18, 2020 — 10:00 AM EST

**Seda Albayrak, Department of Pure Mathematics, University of Waterloo**

"Sparse Automatic Sets"

I will present results in the theory of sparse automatic sets in three different contexts: the theory of algebraic power series, unlikely intersections, and the theory of representations in additive bases.

Online

Friday, November 13, 2020 — 2:30 PM EST

**Joe Driscoll, University of Leeds**

"Deformations of Asymptotically Conical G2-Instantons"

Tuesday, November 3, 2020 — 11:00 AM EST

**Chris Sangwin, University of Edinburgh**

**"Assessing students' proofs online"**

In this seminar I will describe how we, at the University of Edinburgh, have tried to help students learn proof through online assessment. This is ongoing work, driven by a practical need and constrained by current technology which cannot automatically assess students' free form proof. The seminar will discuss the nature of elementary proof more generally.

Monday, November 2, 2020 — 4:00 PM EST

**Andreas Thom, Technische Universität Dresden**

"Finitary approximation properties of groups"

Motivated by the study of equations over groups, I will explain various finitary approximation properties of groups. Related to this, old questions of Ulam will reappear and we will motivate and discuss the notion of stability of solutions and almost solutions to algebraic equations.

Zoom meeting: https://zoom.us/j/92568762391?pwd=djh2Q2R6OFlHbUtCUEZsbE42ZDhxZz09

Wednesday, October 28, 2020 — 2:00 PM EDT

**Seda Albayrak, Department of Pure Mathematics, University of Waterloo**

"A refinement of Christol’s theorem"

Monday, October 19, 2020 — 4:00 PM EDT

**Sergey Grigorian, University of Texas Rio Grande Valley**

"Smooth loops"

Friday, October 9, 2020 — 2:30 PM EDT

**Niky Kamran, McGill University**

"Non-uniqueness for the anisotropic Calderon problem"

Thursday, October 1, 2020 — 4:00 PM EDT

**Daniel Perales Anaya, Department of Pure Mathematics, University of Waterloo**

"Free Probability and Non-crossing Partitions"

Wednesday, September 30, 2020 — 2:30 PM EDT

**Seda Albayrak, Department of Pure Mathematics, University of Waterloo**

"A Strong version of Cobham’s theorem"

Friday, September 25, 2020 — 2:30 PM EDT

**Michael Albanese, UQAM**

"Almost Complex Structures on Rational Homology Spheres"

Friday, September 18, 2020 — 2:30 PM EDT

**Chao Li, Princeton University**

"Geometric comparison theorems for scalar curvature lower bounds"

Monday, August 10, 2020 — 1:30 PM EDT

**Zsolt Tanko, Department of Pure Mathematics, University of Waterloo**

"Coefficient spaces arising from locally compact groups"

Wednesday, July 22, 2020 — 4:30 PM EDT

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

"Generatingfunctionology: basics and approximation"

A generating function is a device for studying a sequence by trapping it in the coefficients of a power series. I'll give a brief crash course on "generatingfunctionology", and show you how to write down the generating function of Fibonacci numbers. This gives, for instance, an exact formula for the nth Fibonacci number. We don’t usually care whether the series converges, and work in the setting of “formal” power series.

Tuesday, July 21, 2020 — 10:00 AM EDT

**Ehsaan Hossain, Department of Pure Mathematics, University of Waterloo**

"Recurrence in Algebraic Dynamics"

Let $\varphi:X\dashrightarrow X$ is a rational mapping of an algebraic variety $X$ defined over $\C$. The *orbit* of a point $x\in X$ is the sequence $\{x,\varphi(x),\varphi^2(x),\ldots\}$. Our basic question is: how often does this orbit intersect a given closed set $C$? Thus we are interested in the *return set*

\[ E := \{n\geq 0 : \varphi^n(x)\in C\}. \]

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

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 promised 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.