## 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, November 21, 2017 — 1:30 PM EST

**Parham Hamidi, Department of Pure Mathematics, University of Waterloo**

"Integral advice on going up in the world^{1}!"

Now that we are done with definitions and a few boring results about integral homomorphisms, we can prove the Lying over and Going up Theorems. I will prove Nakayama’s Lemma using a simple trick and talk about some of its applications. Finally we would see how the Lying over and Going up Theorems can be interpreted geometrically in number theory in the theory of ramifications.

Tuesday, November 21, 2017 — 2:30 PM EST

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

"Isomorphisms that cannot be coded by computable relations -- Part 2"

Last time, we saw why it is so useful to code an isomorphism by the image of a computable relation and also explored some cases where this is always possible. We now turn to constructing a pair of structures where this is not possible. That is, we construct two structures -- isomorphic to $(\omega, <)$ -- where this method of establishing the degree of the isomorphism between them will not work.

MC 5413

Tuesday, November 21, 2017 — 4:00 PM EST

**Deirdre Haskell, McMaster University**

"Residue field domination in theories of valued fields"

Wednesday, November 22, 2017 — 4:30 PM EST

**Mehdi Karimi, Department of Combinatorics & Optimization, University of Waterloo**

"Sum-of-Squares Proofs in Optimization"

The old concept of sum-of-squares found its way into optimization and even machine learning. I will talk about this quickly evolving research area known as convex algebraic geometry.

MC 5501

Thursday, November 23, 2017 — 1:30 PM EST

**Divyum Sharma, Department of Pure Mathematics, University of Waterloo**

"Joint distribution of the base-*q* and Ostrowski digital sums"

Friday, November 24, 2017 — 2:30 PM EST

**Xinliang An, University of Toronto**

"On Singularity Formation in General Relativity"

Friday, November 24, 2017 — 3:30 PM EST

**Arthur Mehta, Department of Pure Mathematics, University of Waterloo**

"Chromatic numbers and a Lovász type inequality for non-commutative graphs"

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