## 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

Tuesday, October 22, 2019 — 2:00 PM EDT

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

"REVERSE MATHEMATICS"

While most of mathematics is concerned with using a set of axioms to prove theorems, reverse mathematics is a relatively new form of mathematical logic that seeks to determine which axioms are required to prove certain theorems. This gives a notion of the “strength” of a certain theorem by looking at which theorems imply it, and which are implied by it.

Friday, October 11, 2019 — 1:30 PM EDT

**Gabriel Islambouli, Deaprtment of Pure Mathematics, University of Waterloo**

"Smooth 4-manifolds and the Pants Complex"

Thursday, October 10, 2019 — 11:00 AM EDT

**Marco Handa, Department of Pure Mathematics, University of Waterloo**

"NIP IV"

We begin section 2.2.1 of Simon's Guide to NIP theories.

MC 5413

Wednesday, October 9, 2019 — 3:30 PM EDT

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

"Entropy of Self-similar Measures"

It is known that a self-similar measure is either purely singular or absolutely continuous. Despite this, for most measures we cannot say which case we are in. One technique that has proved promising is the study of the Garsia Entropy of the measure. In this talk I will discuss the history, properties and recent results for self-similar measures and Garsia Entropy.

MC 5417

Tuesday, October 8, 2019 — 2:30 PM EDT

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

"Normal forms of dominant polynomial morphisms of the affine plane"

Tuesday, October 8, 2019 — 1:30 PM EDT

**Ertan Elma, Department of Pure Mathematics, University of Waterloo**

"Discrete Mean Values of Dirichlet *L*-functions"

Let χ be a Dirichlet character modulo a prime number *p* ⩾ 3 and let \mathfrak *a*_χ:=(1-χ(-1))/2. Define the mean value

\begin{align*}

\mathcal{M}_{p}(s,\chi):=\frac{2}{p-1}\sum_{\substack{\psi \bmod p\\\psi(-1)=-1}}L(1,\psi)L(s,\chi\overline{\psi})

\end{align*}

for a complex number *s* such that *s*≠ 1 if \mathfrak a _χ=1.

Monday, October 7, 2019 — 4:00 PM EDT

**Jeffrey Diller, University of Notre Dame**

"A transcendental first dynamical degree"

Friday, October 4, 2019 — 2:30 PM EDT

**Fenglong You, University of Alberta**

"Structures of relative Gromov-Witten theory"

Thursday, October 3, 2019 — 11:00 AM EDT

**Steven Lazzaro, McMaster University**

"NIP III"

We begin section 2.2 of Simon's Guide to NIP theories.

MC 5413

Wednesday, October 2, 2019 — 3:30 PM EDT

**Carlos Cabrelli, Universidad de Buenos Aires**

"Recent Advances in Dynamical Sampling"

Tuesday, October 1, 2019 — 2:00 PM EDT

**Matthew Harrison-Trainor, Victoria University of Wellington**

"Introcomputability"

Monday, September 30, 2019 — 11:30 AM EDT

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

"The valuative tree at infinity"

To study the dynamics of a polynomial map on the complex affine plane we must be able to study the behavior of the mapping near the origin and near infinity. The study of the dynamics near a point leads to the notion of the valuative tree at the origin of the affine plane. To study the dynamics near infinity, we introduce a new but analogous object,the valuative tree at infinity, which will be the subject of this lecture.

MC 5403

Friday, September 27, 2019 — 11:00 AM EDT

**Sylvie Davies, Department of Pure Mathematics, University of Waterloo**

"Algebraic Approaches to State Complexity of Regular Operations"

Thursday, September 26, 2019 — 11:00 AM EDT

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

"NIP II"

We finish up section 2.1 and begin section 2.2 of Simon's Guide to NIP theories.

MC 5413

Wednesday, September 25, 2019 — 3:30 PM EDT

**Mizanur Rahaman, Department of Pure Mathematics, University of Waterloo**

"Bisynchronous games and factorizable maps"

Tuesday, September 24, 2019 — 2:00 PM EDT

**Dino Rossegger, Department of Pure Mathematics, University of Waterloo**

"The complexity of Scott sentences of scattered linear orders -- Part II"

Monday, September 23, 2019 — 4:00 PM EDT

**Alex Iosevich, University of Rochester**

"Analytic, geometric and combinatorial aspects of the Falconer distance conjecture"

Monday, September 23, 2019 — 2:30 PM EDT

****Note time and room change****

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

"Introduction to the valuative tree"

Thursday, September 19, 2019 — 1:00 PM EDT

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

"C*-covers of semicrossed products"

Wednesday, September 18, 2019 — 3:30 PM EDT

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

"On the structure of invertible elements in Fourier-Stieltjes algebras"

Tuesday, September 17, 2019 — 2:00 PM EDT

**Dino Rossegger, Department of Pure Mathematics, University of Waterloo**

"The complexity of Scott sentences of scattered linear orders"

Tuesday, September 17, 2019 — 1:30 PM EDT

**J.C. Saunders, Ben Gurion University of Negev**

"Diophantine equations involving the Euler totient function"

We deal with various Diophantine equations involving the Euler totient function. In particular, for $a,b,c,m,n\in\mathbb{N}$ with $m\geq 2$ we study the equations $\varphi(ax^m)=\frac{b\cdot n!}{c}$ and $\varphi\left(\frac{b\cdot n!}{c}\right)=ax^m$ where $\varphi(x)$ is the Euler totient function. We also deal with similar equations involving Lucas sequences of the first kind and second kind, generalising the work of Luca and Stanica.

Thursday, September 12, 2019 — 4:30 PM EDT

**Adina Goldberg, Department of Pure Mathematics, University of Waterloo**

"This title contains information"

How can we mathematically test the claim made in the title? In this talk, we will learn about Claude Shannon's entropy and determine if it gives us the best measure of informativeness. If you can picture the graph of a logarithm, you are well prepared.

MC 5501

Monday, September 9, 2019 — 4:00 PM EDT

**Shai Ben-David, School of Computer Science, University of Waterloo**

"A basic machine learning problem is independent of set theory"

Thursday, August 15, 2019 — 10:00 AM EDT

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

"Computability of Walker's Cancellation Theorem"

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