## Besøksadresse

Niels Henrik Abels hus (kart)

Moltke Moes vei 35

0851
OSLO

Norway

Tid og sted:
8. des. 2016 11:15 - 13:00,
B 738

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A continuation of part I.

Nacira Agram (University of Oslo) gives a lecture with the title: Model Uncertainty Stochastic Mean-Field Control.

Rodwell Kufakunesu (University of Pretoria, South Africa) gives a lecture with the title: Pricing and hedging quanto commodity options.

Tid:
20. des. 2016 14:15

Daniel Roy (Department of Statistical Sciences, University of Toronto) will give a seminar in the lunch area, 8th floor Niels Henrik Abels hus at 14:15.

The 17th Danish-Norwegian workshop in Operator algebras will take place at Lysebu (Oslo), January 5 - 8, 2017, with support from the Foundation for Danish-Norwegian Cooperation. It will start with lunch on Thursday, January 5, and end after breakfast on Sunday, January 8.

One day of the workshop will be devoted to commemorate our dear colleague and friend, Ola Bratteli, who passed away in 2015 and would have turned 70 in October 2016. Ola’s nearest collaborators over the years (George Elliott, David Evans, Akitaka Kishimoto, Palle Jorgensen and Derek Robinson) will then give talks reflecting the great impact of Ola’s work within several topics (e.g. AF-algebras, derivations, C*-dynamical systems, mathematical physics, wavelets).

Participation is possible only by personal invitation from the organizing committee.

The programme will be made available around the beginning of December.

A conference celebrating the work of Ragni Piene on the occasion of her 70th birthday.

Tid og sted:
7. des. 2016 10:15 - 12:00,
NHA, seminarrom B81

John Quigg, Arizona State University (Tempe), USA, will give a talk with title "The Pedersen rigidity problem".

University of Abstract: If \alpha is an action of a locally compact abelian group G on a C*-algebra A, Takesaki-Takai duality recovers (A,\alpha) up to Morita equivalence from the dual action of \widehat{G} on the crossed product A\rtimes_\alpha G. Given a bit more information, Landstad duality recovers (A,\alpha) up to isomorphism. In between these, by modifying a theorem of Pedersen, (A,\alpha) is recovered up to outer conjugacy from the dual action and the position of A in M(A\rtimes_\alpha G). Our search (still unsuccessful, somehow irritating) for examples showing the necessity of this latter condition has led us to formulate the "Pedersen rigidity problem". We present numerous situations where the condition is redundant, including G discrete or A stable or commutative. The most interesting of these "no-go theorems" is for locally unitary actions on continuous-trace algebras. This is joint work with Steve Kaliszewski and Tron Omland.

Tid:
6. des. 2016 14:15

Riccardo De Bin (Department of Mathematics, University of Oslo) will give a seminar in the lunch area, 8th floor Niels Henrik Abels hus at 14:15.

Tid og sted:
6. des. 2016 10:15 - 12:00,
B 738

Framed correspondences were invented and studied by Voevodsky in the early 2000-s, aiming at the construction of a new model for motivic stable homotopy theory. Joint with Ivan Panin we introduce and study framed motives of algebraic varieties basing on Voevodsky's framed correspondences. Framed motives allow to construct an explicit model for the suspension P^{1}-spectrum of an algebraic variety. Framed correspondences also give a kind of motivic infinite loop space machine. They also lead to several important explicit computations such as rational motivic homotopy theory or recovering the celebrated Morel theorem that computes certain motivic homotopy groups of the motivic sphere spectrum in terms of Milnor-Witt K-theory. In these lectures we shall discuss basic facts on framed correspondences and related constructions.

Tid og sted:
2. des. 2016 11:15 - 12:00,
NHA bygget 9 etg B91

**Stereolithography - A Powerful Tool to Create almost Everything**

Stereolithography or "SLA" printing is a powerful and widely used 3D printing technology for creating prototypes, models, and fully functional parts for production. This additive manufacturing process works by focusing an ultraviolet (UV) laser onto a vat of liquid resin. Layer by layer formation of a polymeric network allows printing parts that are almost impossible to create with other processes.At Formlabs, a startup that originated out of the MIT Media lab in 2011, we work on all aspects of SLA printing; we develop and manufacture 3D printers, resins, and software. In this talk, I will give a detailed overview of the printer technology, the chemistry of the materials, and how to use SLA for lots of exciting applications.

Tid og sted:
30. nov. 2016 10:15 - 12:00,
NHA B81

Abstract: We first discuss C*-simplicity and the unique trace property for discrete groups in light of recent years' development. In particular, we consider amalgamated free products, and give conditions for such to be (and fail to be) C*-simple. Then we define radical and residual classes of groups, and explain that there exists a radical detecting C*-simplicity, in a similar way as the amenable radical detects the unique trace property. The talk is based on joint work with Nikolay A. Ivanov from Sofia University, Bulgaria.

Tid og sted:
29. nov. 2016 10:15 - 12:00,
B 738

Hopkins, Kuhn, and Ravenel proved that, up to torsion, the Borel-equivariant cohomology of a G-space with coefficients in a height n-Morava E-theory is determined by its values on those abelian subgroups of G which are generated by n or fewer elements. When n=1, this is closely related to Artin's induction theorem for complex group representations. I will explain how to generalize the HKR result in two directions. First, we will establish the existence of a spectral sequence calculating the integral Borel-equivariant cohomology whose convergence properties imply the HKR theorem. Second, we will replace Morava E-theory with any L_n-local spectrum. Moreover, we can show, in some sense, a partial converse to this result: if an HKR style theorem holds for an E_\infty ring spectrum E, then K(n+j)_* E=0 for all j\geq 1. This partial converse has applications to the algebraic K-theory of structured ring spectra.

Tid og sted:
24. nov. 2016 14:15 - 16:00,
B638, NH Abels hus

Tid:
22. nov. 2016 14:15

Peter Müller (University of Texas at Austin) will give a seminar in the lunch area, 8th floor Niels Henrik Abels hus at 14:15.

Tid og sted:
22. nov. 2016 10:15 - 12:00,
B 738

We compute the generalized slices (as defined by Spitzweck-Østvær) of the motivic spectrum KQ in terms of motivic cohomology and generalized motivic cohomology, obtaining good agreement with the situation in classical topology and the results predicted by Markett-Schlichting.

Tid og sted:
16. nov. 2016 10:15 - 11:00,
Niels Henrik Abels hus, room 1036

Kristina Rognlien Dahl (University of Oslo) is giving her inaugural lecture with the title: Stochastic analysis meets risk and reliability theory.

Tid og sted:
14. nov. 2016 14:00 - 14:45,
Niels Henrik Abels hus, room 637

Olivier Menoukeu Pamen (African Institute for Mathematical Sciences, Ghana and University of Liverpool) gives a lecture with the title: Strong Rate of Convergence for the Euler-Maruyama Approximation of SDEs with Irregular Drift Coefficients.

Tid og sted:
14. nov. 2016 13:15 - 14:00,
Niels Henrik Abels hus, room 637

Rajeev Bhaskaran (Indian Statistical Institute, Bangalore, India) gives a lecture with the title: On the connection between SPDE’s and diffusions arising out of an SDE.

Tid og sted:
10. nov. 2016 14:15 - 16:00,
B638, NH Abels hus

Tid og sted:
10. nov. 2016 14:15 - 16:00,
B735

Michael Whittaker from University of Glasgow will give a talk with title: New directions in self-similar group theory

Abstract: A self-similar group (G,X) consists of a group G acting faithfully on a homogeneous rooted tree such that the action satisfies a self-similar condition. In this talk I will generalise the above definition to faithful groupoid actions on the path space of more general graphs. This new definition allows us to work out the structure of the KMS state space of associated Toeplitz and Cuntz-Pimsner algebras. This is joint work with Marcelo Laca, Iain Raeburn, and Jacqui Ramagge.

Tid og sted:
9. nov. 2016 10:15 - 12:00,
B81

Rasmus Bryder (University of Copenhagen) will give a talk with title: Twisted crossed products over C*-simple groups

Abstract: A twisted C*-dynamical system consists of a C*-algebra, a discrete group and a "twisted" action of the group on the C*-algebra, i.e., the group acts by automorphisms on the C*-algebra in a manner determined by a 2-cocycle of the group into the unitary group of the C*-algebra. Whenever the 2-cocycle (or twist) is trivial, the action is given by a group homomorphism of the group into the automorphism group of the C*-algebra. We consider twisted C*-dynamical systems over C*-simple groups (i.e.,groups whose reduced group C*-algebra is simple) and how C*-simplicity affects the ideal structure of reduced crossed products over such dynamical systems.