September 23, 2014

Operator Algebras Seminars
July 2014 - June 2015

Seminars are generally held every Tuesday and Thursday at 2:10 pm in Room 210.
Hosted by the Fields Institute
Fr For more information about this program please contact
George Elliott
Upcoming Seminars: every Tuesday and Thursday at 2 pm Room 210

September 22, 2014

Alessandro Vignati
On what I learnt in Glasgow about the UCT (Part 1)

I will present an introduction on the UCT and KK-theory and a collection of results related to the UCT in the TAF case. This seminar will follow the lectures of Marius Dadarlat and Christian Voigt in a recent Masterclass in Glasgow.

September 23, 2014
Jeffery Im
September 25, 2014
Juno Jung
Past Seminars

August 21, 2014

Jeffrey Im,
Nuclear dimension and Z-stability

We will sketch the original construction of the Jiang-Su algebra and discuss some of its properties. Apart from serving as the first (and only) example of its kind, understanding its role in K- theoretic classification of simple separable nuclear of C*-algebras has been of great interest in recent years. A number of results indicate that the largest class of C*-algebras for which Elliott's classification conjecture can hold is for those which are also Z- stable. Various disparate regularity properties, each of which is helpful for classification, arise as a consequence of being Z-stable. A well-known conjecture characterizing manifestations of Z-stability in a certain class of C*-algebras is the Toms-Winter conjecture. We discuss one of the properties, finite nuclear dimension, and progress on the conjecture.

August 21, 2014
3:15 pm

Juno Jung,
The necessity of quasidiagonality and unique tracial states

On Matui and Sato's paper, titled "Decomposition rank of UHF- absorbing C*-algebras'", proves that if A is a unital separable simple C*-algebra with a unique tracial state, then if A is nuclear, quasidiagonal and has strict comparison or projections, then the decomposition rank of A is at most 3. As a corollary, a partial affirmation of the Toms and Winters conjecture can be proven. In this talk, we focus on how quasidiagonality and having a unique tracial state are necessary conditions for this theorem.

August 19, 2014

James Lutley, University of Toronto
AF algebras of higher rank graphs
We will introduce sufficient and necessary conditions to ensure that the algebras associated with a higher rank graph are AF. These algebras are the Toeplitz extension, which has a representation on finite paths, and the main algebra, represented on infinite paths, which correspond to ultrafilters of the finite path space. We will discuss what obstructions exist, and whether or not the quotient can be AF when the Toeplitz extension is not.






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