The 8th Øresund symposium on non-commutative analysis and non-commutative geometry, May 14, 2014, Lund

General info

This event will take place at the Centre for Mathematical Sciences, Lund University, on May 14, 2014, and is organized by Johan Öinert (LU) and Søren Eilers (KU). Register by sending an e-mail to Johan ( johan.oinert (ª) ). In your e-mail, please indicate if you are willing to give a talk.

Wifi access will be available.

Sponsored by the Royal Swedish Academy of Sciences.


All talks are given in room MH:309A which is located 2 floors above the ground floor.
At noon, there will be an organized lunch at restaurant Moroten & Piskan.

Wednesday, May 14, 2014

10.15-10.30: COFFEE

10.30-10.35: Johan & Søren say Welcome!

10.35-11.20: Toke talks about Partial actions and KMS states on relative graph C*-algebras

11.20-11.30: Discussion / short break

11.30-12.00: Yacin talks about Interpolation of quadratic norms

12.00-13.30: Organized lunch nearby the math building

13.30-14.15: Stuart talks about Regularity properties for nuclear C*-algebras

14.15-14.25: Discussion / short break

14.25-14.55: James talks about On classifying extensions of C*-algebras

14.55-15.15: Discussion / COFFEE break

15.15-16.00: Jan talks about Bimodules in crossed products and regular inclusions of finite factors

16.00-16.10: Discussion / short break

16.10-16.55: Yasuhiko talks about Elementary amenable groups are quasidiagonal

16.55-17.05: Discussion & closing

18.00-**.**: Dinner (in the city centre of Lund)

Participants & abstracts of talks

Toke Meier Carlsen (Norwegian University of Science and Technology, Norway)
Partial actions and KMS states on relative graph C*-algebras

In this talk I will tell you about the preprint "Partial actions and KMS states on relative graph C*-algebras" (arXiv:1311.0912) which I have recently written together with Nadia Larsen from Oslo. Relative graph C*-algebras were introduced by Muhly and Tomforde as generalizations of both graph C*-algebras and their Toeplitz extensions. In our paper, Nadia and I realize relative graph C*-algebras as partial crossed products and use this to characterize the KMS states of certain actions on arbitrary relative graph C*-algebras. We thereby obtain a complete concrete description of the convex set of all KMS states for a big class of graphs which includes all finite graphs.

Yacin Ameur (Lund University, Sweden)
Interpolation of quadratic norms

Given two Hermitian norms ||.||_0 and ||.||_1 on a finite-dimensional space, it is well-known how to construct the (Calderon) interpolation space of a given exponent t. This gives a new Hermitian norm ||.||_t with the property that the corresponding operator norms satisfy the "convexity estimate" ||T||_t \leq ||T||_0^{1-t}||T||_1^t for all operators T. In quadratic interpolation one asks for more general "exact interpolation norms". The quest for such norms is finished in the sense that there is a complete characterization of the most general one. I will give a brief overview of how this works. I believe that the construction will be of interest also in other contexts.

Stuart White (University of Glasgow, United Kingdom)
Regularity properties for nuclear C*-algebras

I'll discuss how recent progress in the structure theory of simple nuclear C*-algebras, relates to results on injectivity and hyperfiniteness for von Neumann algebras.

James Gabe (University of Copenhagen, Denmark)
On classifying extensions of C*-algebras

We will present a few results on extensions of C*-algebras. The first asserts that if a stable C*-algebra B has a certain ideal related version of the corona factorization property then any "full" extension by B, fullness being in an ideal related setting, is weakly residually nuclearly absorbing. Combining this result with a result on the primitive ideal space of corona algebras, yields a Weyl-von Neumann type theorem a la Kirchberg.

These two results imply, that if B statisfies the above Weyl-von Neumann Theorem and A is any nuclear, separable C*-algebra, then any non-unital extension of A by B is classified up to strong unitary equivalence by a certain action of Prim(B) on A together with an induced ideal related KK^1-element. This is joint work with Efren Ruiz.

Jan Cameron (Vassar College, USA)
Bimodules in crossed products and regular inclusions of finite factors


Yasuhiko Sato (Kyoto University, Japan)
Elementary amenable groups are quasidiagonal


Other participants (who are not giving talks) include:

Bartosz Malman (Lund University, Sweden)
Clarisson Rizzie Pacheca Canlubo (University of Copenhagen, Denmark)
Ehud Meir (University of Copenhagen, Denmark)
Erik Christensen (University of Copenhagen, Denmark)
Hiroshi Ando (University of Copenhagen, Denmark)
Johan Öinert (Lund University, Sweden)
Liguang Wang (Qufu Normal University, China & University of Copenhagen, Denmark)
Martin Søndergaard Christensen (University of Copenhagen, Denmark)
Matias Lolk (University of Copenhagen, Denmark)
Niek de Kleijn (University of Copenhagen, Denmark)
Roger Smith (Texas A&M University, USA)
Rune Johansen (University of Copenhagen, Denmark)
Sanaz Pooya (Ferdowsi University of Mashhad, Iran & Lund University, Sweden & University of Copenhagen, Denmark)
Sara Arklint (University of Copenhagen, Denmark)
Søren Eilers (University of Copenhagen, Denmark)
Søren Knudby (University of Copenhagen, Denmark)
Tyrone Crisp (University of Copenhagen, Denmark)

Last update: 2014-05-13 @ 23.15 CET