## 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

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

Thursday, April 25, 2019 — 3:00 PM EDT

****Rescheduled from April 19. Note new day/time/room****

**Shubham Dwivedi, Department of Pure Mathematics, University of Waterloo**

"A gradient flow of isometric $G_2$ structures"

Wednesday, April 17, 2019 — 3:30 PM EDT

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

"Non-triviality of the Bounded Jump Hierarchy - Part 3"

We finish the proof that for all $B$, there is some set $A$ with $B <_{bT} A <_{bT} B^b$. We determine $\hat{h}_A$ and $\hat{h}_C$ as promised, taking into account the restrictions imposed by the construction, and prove that our choices are correct.

MC 5413

Monday, April 15, 2019 — 11:30 AM EDT

**Nigel Pynn-Coates, University of Illinois at Urbana-Champaign**

"Asymptotic valued differential fields and differential-henselianity"

Wednesday, April 10, 2019 — 3:30 PM EDT

**Clifford Bearden, University of Texas at Tyler**

"A module version of the weak expectation property"

Wednesday, April 10, 2019 — 3:30 PM EDT

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

"Non-triviality of the Bounded Jump Hierarchy - Part 2"

We continue with the proof that for all $B$, there is some set $A$ with $B <_{bT} A <_{bT} B^b$. We start the main construction itself, check that the requirements eventually settle and are met, and we investigate the correct $\hat{h}_A$ and $\hat{h}_C$ as promised.

MC 5413

Friday, April 5, 2019 — 2:30 PM EDT

**Spiro Karigiannis, Department of Pure Mathematics, University of Waterloo**

"A curious system of second order nonlinear PDEs for $\mathrm{U}(m)$-structures on manifolds"

Thursday, April 4, 2019 — 12:00 PM EDT

**Nick Manor, Unviersity of Waterloo**

"Exact Groups"

There are two notions of exactness for groups, but they are not known to be equivalent outside the discrete case. I will show how we can extend this equivalence to include two larger classes of groups.

MC 5403

Wednesday, April 3, 2019 — 4:30 PM EDT

**Ben Moore, University of Waterloo**

"A proof of the Hell-Neˇsetˇril Dichotomy via Siggers Polymorphism"

Wednesday, April 3, 2019 — 3:30 PM EDT

"The numerical range of quaternion matrices with respect to involutions"

Wednesday, April 3, 2019 — 3:30 PM EDT

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

“Non-triviality of the Bounded Jump Hierarchy - Part 1”

Monday, April 1, 2019 — 4:00 PM EDT

**Jan Minac, University of Western Ontario**

"The 13th mysterious room of a palace of absolute Galois 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

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.