# Events

### Logic Seminar

Tuesday, March 28, 2017 - 11:00 AM EDT

"On the Computable Categoricity of Trees of Finite Height"

### Computability Learning Seminar

Tuesday, March 28, 2017 - 3:00 PM EDT

Jonny Stephenson, Department of Pure Mathematics, University of Waterloo

"The c.e. embeddability condition"

We will discuss the c.e. embeddability condition, which is a condition introduced by Richter, and which provides an exact characterization of those structures which do not code any non-c.e. sets. Such structures cannot have nontrivial Turing or enumeration degrees. If time permits, we will demonstrate that linear orderings have the c.e. embeddability condition.

MC 5403

### Number Theory Seminar

Thursday, March 30, 2017 - 1:30 PM EDT

Oleksiy Klurman, University College London

"Multiplicative functions over the function fields"

Thursday, March 30, 2017 - 4:00 PM EDT

Anton Mosunov (Pure Mathematics) and Luis Antonio Ruiz (Combinatorics & Optimization), University of Waterloo

"Tomato Packing and Lettuce-Based Crypto"

Lettuce is good for you. Lattices are good for humanity. We are going to present some nutritious facts about lattices and convince you that they are good for your mathematical diet. Anton will explain the importance of lattices in the tomato/orange/sphere packing problem, and Antonio will show you that many portions of lattices a day may keep you safe from quantum hackers.

MC 5501

### Geometry and Topology Seminar

Friday, March 31, 2017 - 2:30 PM EDT

Ben Sibley, Simons Center, Stony Brook University

"Limits and bubbling sets for the Yang-Mills flow on Kaehler manifolds"

### Analysis Seminar

Friday, March 31, 2017 - 3:30 PM EDT

Jaspar Wiart, Department of Pure Mathematics, University of Waterloo

"The Jacobson Radical of Certain Semicrossed Products"

We study the Jacobson radical of the semicrossed product $A\times_\alpha P$ when $A$ is a simple C*-algebra and $P$ is either a subsemigroup of an abelian group or a free semigroup. A full characterization is obtained for a large subset of these semicrossed products and we apply our results to a number of examples.

MC 5417