## 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

Wednesday, May 31, 2023 3:00 PM EDT

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

**"Restricted Zilber Trichotomy"**

We will be reading Ben Castle’s paper.

MC 4060

Wednesday, May 31, 2023 1:30 PM EDT

**Ada Chan, York University**

**"Complex Hadamard matrices and association schemes, Part 1"**

Complex Hadamard matrices and spin models are special cases of type-II matrices. In the 1980s, Vaughan Jones used spin models to construct link invariants and representations of braid groups. The term *type II* was coined after the second Reidemeister move of link diagrams. In 1990s, Jaeger and Nomura discovered the surprising connection of spin models and association schemes.

Wednesday, May 31, 2023 1:00 PM EDT

**Francisco Villacis, Department of Pure Mathematics, University of Waterloo**

**"An Introduction to GIT Quotients"**

Wednesday, May 31, 2023 11:30 AM EDT

**David Chodounsky, Institute of Mathematics of the Czech Academy of Sciences**

**"Countable chromatic number of definable graphs via games"**

We define games which characterize countable coloring numbers of analytic graphs on Polish spaces. These games can provide simple verification of the countable chromatic number of certain graphs. (Eg. the rational distance graph on the Euclidean plane.) Joint work with Jindrich Zapletal.

MC 5403

Tuesday, May 30, 2023 1:00 PM EDT

**Padraig Daly, Department of Pure Mathematics, University of Waterloo**

**"Quantum superchannels on the space of quantum channels"**

Quantum channels, defined as completely-positive and trace-preserving maps on matrix algebras, are an important object in quantum information theory. In this thesis we are concerned with the space of these channels. This is motivated by the study of quantum superchannels, which are maps whose input and output are quantum channels.

Tuesday, May 30, 2023 11:00 AM EDT

**Dongshu Dai, Department of Pure Mathematics, University of Waterloo**

**"The global loop space"**

We will continue with section 3 of Kapranov and Vasserot's paper.

MC 5403

Tuesday, May 30, 2023 9:30 AM EDT

**Talk #1: Sourabhashis Das, Department of Pure Mathematics, University of Waterloo**

**"On the number of irreducible factors with a given multiplicity in function fields"**

Monday, May 29, 2023 1:00 PM EDT

**J.C. Saunders, Middle Tennessee State University**

**"Primes and composites in the determinant Hosoya triangle"**

Thursday, May 25, 2023 2:30 PM EDT

**Rachael Alvir, Department of Pure Mathematics, University of Waterloo**

**"Reverse Math I"**

In this talk, we will give a preliminary introduction to reverse mathematics. We will be working from a recent book by Damir Dzhafarov and Carl Mummert.

MC 5403

Thursday, May 25, 2023 11:00 AM EDT

**Francisco Villacis, Department of Pure Mathematics, University of Waterloo**

**"An Introduction to Schemes"**

The goal of this talk is to present an overview of Section II.2 of Hartshorne. In particular, I will introduce our main objects of study for this seminar: schemes. I will define what these objects are and study some examples of schemes. If time permits, the second half of the seminar will be devoted to solving some problems from this section of Hartshorne.

MC 5403

Wednesday, May 24, 2023 3:00 PM EDT

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

**"Restricted Zilber Trichotomy"**

We will be reading Ben Castle's paper.

MC 5479

Wednesday, May 24, 2023 1:00 PM EDT

**Sean Monahan, Department of Pure Mathematics, University of Waterloo**

**"Coloured fantastacks"**

Tuesday, May 23, 2023 1:00 PM EDT

**Ravi Mudaliar, Department of Pure Mathematics, University of Waterloo**

**"A Categorical Equivalence between Compact Connected Riemann Surfaces and Function Fields in 1 variable"**

Tuesday, May 23, 2023 11:00 AM EDT

**Ben Webster, Department of Pure Mathematics, University of Waterloo**

**"Vertex algebras, arcs and loops, part 2"**

I'll continue with vertex algebras, with an eye to how they arise in algebraic geometry through arc and loop spaces.

MC 5403

Tuesday, May 23, 2023 9:30 AM EDT

**Talk #1: Logan Batson**

**"The density of integers n relatively prime to the integral part of nα"**

We discuss the distribution of positive integers n that are relatively prime to the integral part of nα. We demonstrate that the density of such integers is 6/π^{2} by separating the cases when α is rational from when α is irrational and using some previous results of Vinogradov, Hardy and Wright.

**Talk #2: Ismael El Yassini**

Friday, May 19, 2023 4:30 PM EDT

**Hanming Liu, Department of Pure Mathematics, University of Waterloo**

**"Living inside 3-manifolds"**

Day to day life gives us a pretty good idea of what it is like living inside 3-dimensional Euclidean space. But what about other 3-manifolds? It turns out that thinking about this question leads to a way of visualizing 3-manifolds without having to visualize 4 or 5-dimensional Euclidean spaces, and to a classification of closed orientable 3-manifolds.

MC 5417

Thursday, May 18, 2023 4:00 PM EDT

**Mehrdad Kalantar, University of Houston**

**"Complexification of operator spaces — Revisited"**

Thursday, May 18, 2023 2:30 PM EDT

**Lorenzo Fatibene, University of Torino**

**"Spin frames vs spin structures: A framework for Dirac fields in interaction with gravity"**

Thursday, May 18, 2023 1:00 PM EDT

**Michael Brannan, Department of Pure Mathematics, University of Waterloo**

**"Some constructions with Hadamard matrices"**

I'll discuss a few constructions involving Hadamard matrices, including: Hadamard graphs, unitary error bases, and mutually unbiased bases.

MC 5403

Wednesday, May 17, 2023 1:30 PM EDT

**Nick Priebe, University of Waterloo**

**"Introduction to Hadamard matrices and their quantum symmetries"**

Continuing last Thursday's talk, we will introduce the Banica-Nicoara quantum symmetry groups of Hadamard matrices. These provide some interesting quantum groups, and in some sense capture some symmetries associated with the matrix.

MC 5403

Tuesday, May 16, 2023 1:00 PM EDT

**Jacques van Wyk, Department of Pure Mathematics, University of Waterloo**

**"The Hodge Decomposition Theorem"**

Tuesday, May 16, 2023 12:30 PM EDT

**Thomas Bray, Department of Pure Mathematics, University of Waterloo**

**"Boundaries and C*-simplicity of (discrete) groups 2"**

I will continue to discuss the contents of the paper “Boundaries of reduced C*-algebras of discrete groups" by Kalantar and Kennedy.

MC 5479

Tuesday, May 16, 2023 11:00 AM EDT

**Ben Webster, Department of Pure Mathematics, University of Waterloo**

**"Vertex algebras, arcs and loops"**

I'll talk about vertex algebras, with an eye to how they arise in algebraic geometry through arc and loop spaces.

MC 5403

Tuesday, May 16, 2023 10:00 AM EDT

**Talk #1**

**Jérémy Champagne, Department of Pure Mathematics, University of Waterloo**

**"Diophantine approximation by linear forms with angular restrictions"**

Thursday, May 11, 2023 1:00 PM EDT

**Nick Priebe, University of Waterloo**

**"Introduction to Hadamard Matrices"**

A brief overview of Hadamard matrices will be given.

MC 5403

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 co-ordinated within our Office of Indigenous Relations.