## Visiting address

Ullevål StadionSognsveien 77B

0855 OSLO

Norway

Time and place:
Oct. 15, 2014 2:15 PM - 4:00 PM,
NHA Hus, B71

Adam Sørensen (UiO) will give a talk with title: Almost commuting matrices

Abstract: Two matrices A,B are said to almost commute if AB is close to BA (in a suitable norm). A question of Halmos, answered by Lin, asks if two almost commuting self-adjoint matrices are always close to two exactly commuting self-adjoint matrices. We will survey what is known about this and similar questions, and report on recent work with Loring concerning how the questions change if we look at real rather than complex matrices.

Time and place:
Oct. 14, 2014 2:15 PM,
Room 107, N.H.Abels House

Kristan Ranestad (Dept. of Math, UiO) gives a seminar in room 107, 1st floor N.H. Abels House at 14:15 Tuesday October 14th. Algebra og statistics: Phylogenetic models from an algebraic geometric viewpoint

Time and place:
Oct. 9, 2014 2:15 PM - 4:00 PM,
B62, NH Abels hus

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

Abelian varieties VII

Time and place:
Oct. 2, 2014 2:15 PM - 4:00 PM,
B62, NH Abels hus

Daniel Larsson, Høgskolen i Buskerud og Vestfold, gives the Seminar in Algebra and Algebraic Geometry:

Abelian varieties VI

Time and place:
Sep. 26, 2014 10:15 AM - 4:00 PM,
Sophus Bugge, seminar room 3.

Time and place:
Sep. 25, 2014 3:00 PM - 3:45 PM,
Pauseareal 10th floor, NHA

Generalized barycentric coordinates and applications

Time and place:
Sep. 25, 2014 2:15 PM - 4:00 PM,
B62, NH Abels hus

Olav Gravir Imenes, Høgskolen i Oslo og Akershus, gives the Seminar in Algebra and Algebraic Geometry:

Abelian varieties V

Time and place:
Sep. 25, 2014 10:15 AM - 11:00 AM,
B91

Victor Haughton, Professor of Radiology at the University of Wisconsin

and Adjunct Research Scientist at Simula Research Laboratory

Time and place:
Sep. 23, 2014 3:15 PM - 4:00 PM,
B1036, 10th floor, NHA

Variational integrators for interconnected Lagrange-Dirac dynamical systems

Time:
Sep. 23, 2014 2:15 PM

Ørnulf Borgan (Department of Mathematics,UiO) gives a seminar

in room 107, 1st floor N.H. Abels House at 14:15 Tuesday September 23rd:

Using cumulative sums of martingale residuals for model checking in nested case-control studies

Time and place:
Sep. 18, 2014 2:15 PM - 4:00 PM,
B62, NH Abels hus

Andrea Hofmann, Høgskolen i Østfold, gives the Seminar in Algebra and Algebraic Geometry:

Abelian varieties IV

Time:
Sep. 17, 2014 2:00 PM - 4:00 PM

Abstract: We show that the discrete duals of the so called free orthogonal quantum groups have the completely contractive approximation property, analogous to the free groups. The proof relies on the structure of representation categories of these quantum groups, on the C*-algebraic structure of SUq(2), and on the free product techniques of Ricard and Xu. This talk is based on joint work with Kenny De Commer and Amaury Freslon.

Time and place:
Sep. 15, 2014 -
Sep. 19, 2014,
The Norwegian Academy of Sciences and Letters

Welcome to the conference on Stochastics of Environmental and Financial Economics. The conference will bring together leading researchers in the fields of stochastic analysis and finance to discuss recent developments and challenges with an edge towards energy, environmental and financial markets.

The conference is organized by the Center of Advanced Studies (CAS), Stochastics of Environmental and Financial Economics. Scientific organizers: Fred Espen Benth and Giulia Di Nunno (UiO).

Time and place:
Sep. 11, 2014 2:15 PM - 4:00 PM,
B62, NH Abels hus

Arne B. Sletsjøe, UiO, gives the Seminar in Algebra and Algebraic Geometry:

Abelian varieties III

Time and place:
Sep. 10, 2014 3:15 PM - 4:15 PM,
B71, NHA

Abstract: Independence has been introduced as a regularity property for pairs of commuting injective group endomorphisms of a discrete abelian group with finite cokernel by Joachim Cuntz and Anatoly Vershik. We discuss various characterisations of this regularity property and show how the statements need to be adjusted when removing the restrictions that the group has to be abelian and that the cokernels have to be finite. Somewhat surprisingly, this leads to the concept of *-commutativity. This property is defined for pairs of commuting self-maps of an arbitrary set. As an examples of *-commutativity, we explain a construction related to the Ledrappier shift and indicate how one obtains examples for independent group endomorphisms from this construction. If time permits, we will point out instances where the two notions have been readily used to obtain C*-algebraic results. Roughly speaking, both notions are designed to give rise to pairs of doubly commuting isometries, which significantly simplifies the analysis of the constructed C*-algebras. This is particularly useful when one tries to generalise results from the case of a single transformation to an action generated by finitely many transformations.

Time and place:
Sep. 4, 2014 2:15 PM - 4:00 PM,
B62, NH Abels hus

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

Abelian varieties II

Time and place:
Aug. 29, 2014 10:15 AM - 11:00 AM,
B1036, NHA

Parabolic optimal control problems with pointwise controls

Time and place:
Aug. 28, 2014 2:15 PM - 4:00 PM,
B62, NH Abels hus

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

Abelian varieties I

Time and place:
Aug. 21, 2014 10:15 AM - 12:00 PM,
B 63

The logic seminar will take place in B63 in NHA on Thursdays from 10.15 to 12.00.

The program is tentative. There are free slots in the program. Contact Dag Normann for suggestions or questions.

Time and place:
Aug. 5, 2014 11:00 AM - 12:00 PM,
B91 Abel Building

**Three-dimensional instability of solitary water waves**

Time and place:
June 18, 2014 2:15 PM - 3:00 PM,
B1036

Jocelyne Bion-Nadal (CNRS and Ecole Polytechnique) holder et seminar med tittelen: Martingale problem for integro-differential operators with path dependent coefficients

Time:
June 17, 2014 2:15 PM

Per A. Mykland (The University of Chicago) og Lan Zhang (University of Illinois at Chicago) give a seminar in Auditorium 4, Vilhelm Bjerknes house, at 14:15, Tuesday June 17th: Assessment of Uncertainty in High Frequency Data: The Observed Asymptotic Variance

Time and place:
June 13, 2014 10:15 AM - 12:00 PM,
B 81

If B is a sub-Hopf algebra of the mod 2 Steenrod algebra, the category of B-modules has subcategories of modules local or colocal with respect to certain Margolis homologies, and corresponding localization and colocalization functors. The Picard groups of these subcategories are sufficient to detect the Picard group of the whole category and contain modules of geometric interest. General results obtained along the way allow us to begin to attack the analogous questions for E(2) and A(2)-modules. Applications include better descriptions of polynomial algebras as modules over the Steenrod algebra, and of the values of certain generalized cohomology theories on the classifying spaces of elementary abelian groups.

Time and place:
June 11, 2014 2:15 PM - 3:00 PM,
B62, NH Abels hus

Gary Kennedy, Ohio State University, gives the Seminar in Algebra and Algebraic Geometry:

Convex bodies associated to spherical varieties

Time and place:
June 11, 2014 11:15 AM - 12:00 PM,
B62, NH Abel's building

Eduardo Esteves (IMPA, Rio de Janeiro), gives the Seminar in Algebra and Algebraic Geometry:

Compactified Jacobians of nodal curve and limit linear series