Events

Ross Willard, Department of Pure Mathematics, University of Waterloo

Graphs, posets, polymorphisms, and the Constraint Satisfaction Problem Dichotomy Conjecture"

To kick of this term's seminar, I will briefly present all the main themes at play in current work on the Constraint Satisfaction Problem Dichotomy Conjecture.

Evgenios Kakariadis, Department of Pure Mathematics University of Waterloo

“Isomorphism Invariants for C*-dynamical systems”

Apart from the strong interest of the non-selfadjoint operator algebra community on dynamics, additional motivation for their examination comes from the recent number theoretic papers of Cornelissen and Marcolli and also from their work in graph theory.

Isaac Goldbring University of Illinois, Chicago

“Model theory of tracial von Neumann algebras and the Connes Embedding Problem”

Von Neumann algebras play an important role in many areas of mathematics, including representation theory, knot theory, and measure theory. In this talk, we will discuss (tracial) von Neumann algebras from a model-theoretic perspective.

Pantelis Eleftheriou, Department of Pure Mathematics, University of Waterloo

Groups definable in o-minimal structures

Let M be an ordered vector space over an ordered division ring D. A subset X of Mn is called “semilinear” if it is a boolean combination of sets defined by linear equations and inequalities with coefficients from D. A ”semilinear group” is a group whose domain and the graph of its multiplication are semilinear sets.

Rahim Moosa, Department of Pure Mathematics, University of Waterloo

"NIP Theories II"

We will continue to read Pierre Simon’s lecture notes.

Calder Daenzer, Penn State University

“T-duality and Picard stacks”

T-dualization is a transform of geometric spaces which, when applied to appropriate space- time models, is supposed to induce an equivalence of string theories.

Ross Willard, Department of Pure Mathematics, University of Waterloo

"Graphs, posets, polymorphisms, and the Constraint Satisfaction Problem Dichotomy Conjecture, Part II"

This is a continuation of last week's seminar. I will have
identify each of the main Maltsev conditions relevant to CSP and some
secondary ones, characterize each main Maltsev condition by a class of
structures which it forbids to be pp-interpretable, and state the

Matthew Wiersma, Department of Pure Mathematics University of Waterloo

“The Banach-Tarski Paradox”

Many of us are familiar with the statement of the Banach-Tarski Paradox. This counterintuitive theorem tells us that it is possible to break a ball into finitely many pieces and rearrange those pieces to form two identical copies of the original ball. In this talk, we will discuss this theorem’s proof and use it to motivate the study of amenable groups.

Michael Hartz, Department of Pure Mathematics, University of Waterloo

"Universal operator algebras for commuting row contractions"

In this talk, we will consider universal operator algebras generated by commuting row contractions satisfying homogeneous polynomial relations. These algebras can be realized as algebras of functions on the varieties defined by the relations.

Omar Leon Sanchez, Department of Pure Mathematics, University of Waterloo

"The model-companion of partial differential fields with an automorphism"

We explain how one can characterize the existentially closed models in terms of differential-algebraic varieties, and then show that this class is elementary using characteristic sets of differential prime ideals.