Tidlegare gjesteforelesninger og seminarer - Side 68

Friday Seminar by Juan Bonachela from the University of Strathclyde (Scotland)

Gregal Vissers, Postdoctoral Fellow , ITA

Robert Yuncken (Univ. Clermont-Ferrand II, France) will give a talk with title: A groupoid approach to pseudodifferential operators

Abstract: Connes introduced the "tangent groupoid" of a manifold as a geometric device for linking a classical pseudodifferential operator to its symbol, yielding a novel proof of the Atiyah-Singer index theorem.  Since then, numerous variations on the tangent groupoid have been produced, each adapted to a different class of pseudodifferential operators.  In this talk we will consider the reverse problem: associating to a given tangent groupoid a pseudodifferential calculus.  We shall show that the kernels of classical pseudodifferential operators are precisely the essentially homogeneous fibrewise distributions on Connes' tangent groupoid.  This leads to a natural pseudodifferential calculus of subelliptic type on a manifold with a filtration on its Lie algebra of vector fields.

Fredrik Meyer, UiO, gives the Seminar in Algebra and Algebraic Geometry:

Modular curves VII

CEES Extra Seminar by Bernard Wood from The George Washington University

Comments on the Galilean limits of Maxwell's equations

 Oda Bjærke, IBV

Convex relaxation, graph cut and continuous max-flow algorithms for image processing and computer vision.

Friday seminar by Michael Crusoe from Michigan State University (US)

Pietro De Poi (Udine), gives the Seminar in Algebra and Algebraic Geometry:

A Severi type theorem on surfaces in P^6

Friday seminar by Patrick Kestemont from the University of Namur, Belgium

Anja Røyne, Postdoc at Physics of Geological Processes, Department of Physics, UiO

Kristian Ranestad, UiO, gives the Seminar in Algebra and Algebraic Geometry:

Modular curves VI

Réamonn Ó Buachalla (IMPAN) will give a talk with title: Noncommutative Kähler structures on quantum homogeneous spaces

Abstract:

Building on the definition of a noncommutative complex structure for a general algebra A, I will introduce the notion of a noncommutative Kähler structure for A. In the special case where A is a quantum homogeneous space, I show that many of the fundamental results of classical Kähler geometry follow from the existence of such a structure: Hodge decomposition, Serre duality, the Hard Lefschetz theorem, the Kähler identities, and collapse of the Frölicher spectral sequence at the first page. We then apply these results to Heckenberger and Kolb's differential calculus for quantum projective space, and show that they have cohomology groups of at least classical dimension. Time permitting, I will also discuss the relationship of this work to Connes proposal to study positive Hochschild cocycles as a starting point for noncommutative complex geometry, and Fröchlich, Grandjean, and Recknagel's definition of a Kähler spectral tuple.

CEES Extra Seminar by Masahito Tsuboi from Uppsala University. 

 Eva Leu (Akvaplan-NIVA)

Eduard Ortega, NTNU, will give a talk with title: Cuntz-Krieger uniqueness theorems

Abstract: I will make a little survey about Cuntz-Krieger uniqueness theorems and how they help to the study of the ideal structure of the rings to which one can apply them. In certain classes of (C*-)algebras this is described as topologically freeness or condition (L). However they are important classes of rings for which are not known Cuntz-Krieger type theorems. I will present a class of rings, that generalize Leavitt path algebras and Passman crossed products, for which I can totally characterize the Cuntz-Krieger uniqueness theorem.

Friday seminar by Vadim B. Fedorov from University of Alaska Fairbanks

Ann-Cecilie Larsen, Post.doc., Dep. of Physics/SAFE, University of Oslo

Parameter-robust finite element discretization and its preconditioning for Biot's consolidation model in poroelasticity

Erik Bédos will give a talk with title: On the Fourier-Stieltjes algebra of a C*-dynamical system

Abstract: When G is a discrete group, its Fourier-Stieltjes algebra B(G) may be described as the set of coefficient functions associated with unitary representations of G on Hilbert spaces. In a similar way, if Sigma=(A, G, alpha, sigma) is a unital discrete twisted C*-dynamical system, one may let the Fourier-Stieltjes algebra B(Sigma) consist of the functions from G x A into A that arise as coefficient functions of equivariant representations of Sigma on Hilbert A-modules. We will explain how B(Sigma) may be organized as an algebra with conjugation, and show that it may be represented as completely bounded multipliers on the full crossed product C*(Sigma). (This is also known to be true for the reduced crossed product). This is part of an ongoing project with Roberto Conti (Rome).

Carl Henrik Gørbitz, Professor - Kjemisk institutt

Arvid Siqveland, Høgskolen i Buskerud og Vestfold, gives the Seminar in Algebra and Algebraic Geometry:

Modular curves V

These are the fifth and and the sixth lectures given by Anders Hansen (Cambridge Univ. and UiO) on Compressed sensing - Theory and Applications.