# Events - 2014

Wednesday, December 10, 2014 — 3:30 PM EST

## "Measuring the relative strength of sets of natural numbers"

Keng Meng (Selwyn) Ng, Nanyang Technological University

Tuesday, November 18, 2014 — 3:30 PM EST

## “Computable Model Theory of Torsion-Free Abelian Groups”

Sam Eisenstat, Department of Pure Mathematics, University of Waterloo

Countable torsion-free abelian groups are very complicated objects in general. We focus on groups that are direct sums of subgroups of $\mathbb{Q}$ and investigate their computability-theoretic properties. We look at degree spectra, categoricity, complexity of presentations, and complexity of the index and isomorphism problems. $\Sigma_{7}$ shows up!

But first, we let Mohammad finish his lemma from last time.

MC 5046

Tuesday, November 11, 2014 — 3:30 PM EST

## "Goncharov's Theorem"

Mohammad Mahmoud, Department of Pure Mathematics University of Waterloo

We continue through the proof of Goncharov’s Theorem from Mcpherson’s research paper.

MC 5046

Tuesday, November 4, 2014 — 10:30 AM EST

## “Adding Gaussian elimination to local consistency checking - 4”

Ross Willard, Department of Pure Mathematics, University of Waterloo

In this fourth of several lectures, I analyze singular pairs of variables, realizing their singu- larity in the congruence lattice of their associated constraint relation.

MC 5158B

Wednesday, October 29, 2014 — 3:30 PM EDT

## “Computability Theoretic Reduction between Pi12Principles”

Denis Hirschfeldt, University of Chicago

Tuesday, October 28, 2014 — 10:30 AM EDT

## “Adding Gaussian elimination to local consistency checking”

Ross Willard, Department of Pure Mathematics, University of Waterloo

In this third of several lectures, I begin the analysis of a template which has a Maltsev polymorphism and which survives the search for an inconsistency outlined in the first two lectures.

Wednesday, October 15, 2014 — 3:30 PM EDT

## Logic Seminar

Rahim Moosa, Department of Pure Mathematics, University of Waterloo

“A model theory for meromorphic dynamics?”

Wednesday, October 1, 2014 — 3:40 PM EDT

## “Complexity of Young’s Lattice”

Alex Wires, Department of Pure Mathematics, University of Waterloo

S M T W T F S
29
30
31
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
1
1. 2019 (1)
1. June (1)
2. 2017 (10)
3. 2016 (29)
4. 2015 (43)
5. 2014 (8)