## 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

**Fall term update:** visit our COVID-19 Information website for more information.

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