Marcin Marciniak , University of Gdansk:
David Evans , University of Cardiff):
Enrico Laeng, Politecnico di Milano (Italy),:
Abstract: It can be challenging to evaluate the exact norms of an operator which is bounded on various spaces indexed by a parameter (e.g., L^p as p varies). We will present a novel approach, based on rearrangements, in the case of the Hardy-Littlewood Maximal operator. We will also discuss the case of the Hilbert transform and some operators related to it, e.g., the truncated Hilbert transform and the discrete Hilbert transform.
Nadia S. Larsen:
Abstract: For a quasi-lattice ordered pair $(G, P)$ in Nica's sense, with $P$ a subsemigroup of the group $G$, and to a product system $X$ over $P$ of right Hilbert bimodules over a $C^*$-algebra $A$, an analogue of the Cuntz-Pimsner algebra of a single bimodule was introduced by Sims and Yeend; this algebra $NO_X$ is universal for Cuntz-Nica-Pimsner representations of the product system. In the talk I will describe how to associate a co-universal $C^*$-algebra to $X$, show that it plays a crucial role in establishing gauge-invariant uniqueness results, which roughly describe faithfulness of representations of $NO_X$ in terms of faithfulness of their restriction to the coefficient algebra $A$ and invariance under a canonical gauge-coaction, and argue that this new object is a kind of reduced crossed product. This is joint work with T. Carlsen, A. Sims and S. Vittadello.
Marcelo Laca, U of Victoria, Canada:
Erling Størmer:
Roberto Conti, University of Rome:
Abstract: The class of Cuntz algebras appears naturally in several contexts and have consequently been thoroughly investigated in the last decades from different points of view. The main purpose of the talk will be to present some of our recent results (obtained jointly with W. Szymanski and J. Kimberley), where we construct and initiate a classification of so-called permutation automorphisms of O_n (2 ² n). The talk will be essentially self-contained and aimed to be accessible to everybody with a basic knowledge of operator algebras.
Erik Alfsen:
Sergei Neshveyev:
Abstract:I will talk about a recent paper by Radulescu http://arxiv.org/abs/0802.3548 on the famous conjecture in the title.
Jacob Shotwell, NTNU:
Abstract: Higher-rank graph C*-algebras were introduced by Kumjian and Pask as generalizations of the higher-rank Cuntz-Krieger algebras and, more generally, directed graph C*-algebras. This talk will introduce the basic definitions and results concerning higher-rank graph C*-algebras and introduce some results concerning their primitive ideal structure. This work follows a strategy similar to that established by Bates, Hong, Raeburn, and Szymanski for directed graph algebras.
George Elliott, University of Toronto, Canada:
Erik Bedos:
Abstract: This is joint work with Tron Omland (NTNU). We will discuss the problem of determining when the full group C*-algebra C*(G) of a countable discrete group G is primitive, that is, has a faithful irreducible representation. This problem is open for non-amenable groups. When G = PSL(n, Z), n >1, we will explain why C*(G) is primitive if and only if n = 2, in which case we can construct an infinite family of faithful irreducible representations. We will also sketch the proof that C*(G) is primitive whenever G is the free product of two non-trivial amenable groups not both of order two.
Amin Dilawar Malik:
Anders Hansen , University of Cambridge, UK:
Abstract: Compressed Sensing is a great tool for solving inverse problems. However, the current theory covers only inverse problems in finite dimensions. In this talk I will show how the theory by Candes and Tao can be extended to include problems in general Hilbert spaces. The tools required come from probability, operator theory and geometry of Banach spaces. I'll give an introduction to what is already known and discuss some of the quite demanding open questions.