## 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** for information on our response to the pandemic.

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

Thursday, August 20, 2015 — 2:00 PM EDT

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

“Embedding Lattices in the Computably Enumerable Degrees (Part 3)”

Wednesday, August 19, 2015 — 1:30 PM EDT

**Anthony McCormick, Pure Math Department, University of Waterloo **

“Iterated Function Systems with Overlap”

Friday, August 14, 2015 — 10:30 AM EDT

**Jim Haley, Pure Mathematics, University of Waterloo**

"Strongly Reductive Operators and Operator Algebras"

Thursday, August 13, 2015 — 2:00 PM EDT

**Jonny Stephenson, Pure Mathematics, University of Waterloo**

"Embedding Lattices in the Computably Enumerable Degrees (continued)"

This talk is a continuation of one given August 6th.

Thursday, August 13, 2015 — 10:30 AM EDT

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

"The Algebraic Kirchberg--Phillips Conjecture"

Wednesday, August 12, 2015 — 10:30 AM EDT

**Zack Cramer, Pure Mathematics, University of Waterloo**

** "**Approximation of Normal Operators by Nilpotents in Purely Infinite $C^*$-algebras"

Friday, August 7, 2015 — 10:30 AM EDT

**Sam Harris, Pure Mathematics, University of Waterloo**

"Kadison Similarity Problem and the Similarity Degree"

Thursday, August 6, 2015 — 2:00 PM EDT

Jonny Stephenson, Pure Mathematics, University of Waterloo

"Embedding Lattices into the Computably Enumerable Degrees"

The question of which finite lattices can be embedded into the c.e.

degrees first arose with the construction of a minimal pair by Yates,

and independently by Lachlan, showing the 4 element Boolean algebra

can be embedded. This result was rapidly generalised to show any

finite distributive lattice can also be embedded. For non-distributive

lattices, the situation is more complicated.

Tuesday, August 4, 2015 — 1:30 PM EDT

**Stanley Burris, Pure Mathematics, University of Waterloo**

"An Introduction to Boole's Algebra of Logic for Classes"

Boole's mysterious algebra of logic, based on the algebra of numbers and idempotent variables, has only been properly understood and justified in the last 40 years, more than a century after Boole published his most famous work, Laws of Thought. In this talk an elementary and natural development of Boole's system, from his partial algebra models up to his four main theorems, will be presented.

Thursday, July 30, 2015 — 4:00 PM EDT

**Richard Mack, Pure Mathematics, University of Waterloo**

"Dual spaces and von Neumann Algebras"

A canonical construction in Linear Algebra is that of the dual space.

In this talk, we consider two questions:

When is a Banach space a dual space?

When is there only one possible predual?

Examples will be presented illustrating that these are not trivial questions, and a major theorem (Sakai's) will be presented giving a broad class of examples for the second question.

Wednesday, July 29, 2015 — 4:30 PM EDT

** Patrick Dornian, Combinatorics and Optimization, University of Waterloo**

"Disproving the Hirsch Conjecture"

Wednesday, July 29, 2015 — 1:30 PM EDT

**Raymond Cheng, Pure Mathematics, University of Waterloo**

"Gutting Bundles on Tori"

Tuesday, July 28, 2015 — 2:30 PM EDT

**Chantal David, Concordia University **

“Averages of Euler products and statistics of elliptic curves

Joint work with D. Koukoulopoulos and E. Smith.”

Tuesday, July 28, 2015 — 10:30 AM EDT

**Shuntaro Yamagishi, Pure Mathematics, University of Waterloo**

"Some additive results in $\mathbb{F}_q[t]$"

We collected several results in $\mathbb{Z}$ of additive number theory and translated to results in $\mathbb{F}_q[t]$. The results we collected are related to slim exceptional sets and the asymptotic formula in Waring's problem, diophantine approximation of polynomials over $\mathbb{Z}$ satisfying divisibility conditions, and the problem of Sidon regarding existence of certain thin sequences.

Monday, July 27, 2015 — 1:30 PM EDT

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

"The Invariant Basis Number Property"

Thursday, July 23, 2015 — 2:00 PM EDT

**Mohammad Mahmoud, Pure Mathematics, University of Waterloo**

"A Class of Structures without a Turing Ordinal"

We continue to show that the class Kw has no Turing Ordinal. We construct a set D which is not enumeration reducible to R_\A for any structure \A in Kw. This will imply directly that if the Turing ordinal exists then it must be strictly greater than 0. On the other hand Joe Miller showed that, for our class, if the Turing Ordinal exists it must be 0. Both statements tell us that the Turing Ordinal can't exist.

Wednesday, July 22, 2015 — 2:30 PM EDT

**Oscar Garcia-Prada, ICMAT, Madrid **

‘'Involutions of Higgs bundle moduli spaces”

Wednesday, July 22, 2015 — 2:30 PM EDT

**Asif Zaman, Department of Mathematics, University of Toronto**

“Bounding the least prime in an arithmetic progression”

Tuesday, July 21, 2015 — 1:00 PM EDT

**Alejandra Vicente Colmenares, Pure Mathematics, University of Waterloo**

*"Semistable rank 2 co-Higgs bundles over Hirzebruch surfaces"*

Monday, July 20, 2015 — 1:30 PM EDT

**Ty Ghaswala, Pure Mathematics, University of Waterloo**

"If you love a group, set it free."

The existence of algebraic topology (even if you claim to know nothing about it) should be enough to convince you that doing topology without group theory is difficult, frustrating, alcoholism inducing, and above all, a disservice to topology. In this talk I hope to convince you, at least for a moment, that thinking about groups while ignoring topology is a disservice to group theory.

Thursday, July 16, 2015 — 2:00 PM EDT

**Mohammad Mahmoud, Department of Pure Mathematics, University of Waterloo **

“The Turing Ordinal”

We present the notion of Turing Ordinal of a class of structures. The Turing Ordinal was introduced by Jockusch and Soare as a computability theoretic method for comparing complexities of classes of structures. We explain an example by Montalban of a class of structures that doesn’t have a Turing Ordinal.

Wednesday, July 15, 2015 — 1:30 PM EDT

**Mohamed El Alami, Pure Math Department, University of Waterloo **

“Rank 2 vector bundles on Inoue Surfaces”

Monday, July 13, 2015 — 1:30 PM EDT

**Brendan Nolan, University of Kent **

“The Dixmier–Moeglin Equivalence”

Thursday, July 9, 2015 — 4:00 PM EDT

**Alejandra Vincente Colmenares, Department of Pure Mathematics, University of Waterloo **

“Stable vector bundles over Riemann surfaces”

Wednesday, July 8, 2015 — 2:30 PM EDT

**Samin Riasat, Pure Math Department, University of Waterloo **

“Division by subtraction, and ordered groups”

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