## Visiting address

Ullevål StadionSognsveien 77B

0855 OSLO

Norway

Time and place:
Apr. 30, 2015 10:15 AM,
Aud. 4 Vilhelm Bjerknes' hus

M.Sc. Anis Awal Ayati ved Matematisk institutt avholder prøveforelesning over oppgitt emne: "Air/sea interactions - modelling and experiments".

Time and place:
Apr. 27, 2015 11:15 AM - 12:00 PM,
Room 1036 (Niels Henrik Abels hus).

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

Time and place:
Apr. 24, 2015 2:30 PM - 3:30 PM,
Rest area 7 th. floor NHA

Abstract: If A×C ≃ B×C, is A ≃ B? We encounter this questions in many contexts, and the answer depends in often very subtle ways on the context, or in fancier language, on the category for which the question is posed. I will discuss some examples from algebra, for instance: does a polynomial ring uniquely determine its ring of coefficients, or in algebraic geometry, for instance: if X, Y, Z are algebraic varieties and X × Z ≃ Y ×Z, is X ≃ Y. Here, even when X,Y,Z are affine spaces, the answer (both yes and no occur) is known only in a few cases. In general, a lot of nice mathematics is involved both in proving positive results and in constructing counterexamples.

Coffee/Tea/Biscuits from 14.00

Time and place:
Apr. 23, 2015 2:15 PM - 4:00 PM,
B62, NH Abels hus

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

A Severi type theorem on surfaces in P^6

Time and place:
Apr. 20, 2015 -
Apr. 24, 2015,
The Norwegian Academy of Sciences and Letters

Welcome to the SECOND 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 also a celebration of professor Bernt Øksendal's 70th anniversary. On Thursday April 23 the program of the conference will mark this big event with a selected list of speakers.

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:
Apr. 16, 2015 2:15 PM - 4:00 PM,
B62, NH Abels hus

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

Modular curves VI

Time and place:
Apr. 16, 2015 2:00 PM - 3:00 PM,
Niels Henrik Abels hus, room 1036

Prof. Dr. Alois Gisler (ETH Zurich, RiskLab Switzerland) holds a seminar with the title "On the Development of the Swiss Solvency Test"

Time and place:
Apr. 15, 2015 3:00 PM,
Sparebank 1

Prof. Dr. Alois Gisler (ETH Zurich, RiskLab Switzerland) holds a seminar with the title "The Reserve Risk of the Chain-Ladder Reserving Method from a New Perspective"

Time and place:
Apr. 15, 2015 2:15 PM - 3:15 PM,
NHA B735

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.

Time and place:
Apr. 13, 2015 12:15 PM - 2:00 PM,
NHA B735

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.

Time and place:
Apr. 10, 2015 2:30 PM - 3:30 PM,
NHA rest area

Modular symmetries have been central to many developments in mathematics since their discovery more than a century ago, including the proof of Fermat´s last theorem. In view of Nature´s love for order and symmetry, it is surprising that modular symmetry has not been found in the real world – until now.

Coffee/Tea/Biscuits from 14.00

Time and place:
Apr. 10, 2015 10:15 AM - 11:15 AM,
NHA B1036

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

Time and place:
Apr. 10, 2015 -
Apr. 11, 2015,
The Norwegian Academy of Sciences and Letters

Time and place:
Apr. 8, 2015 2:15 PM - 3:00 PM,
NHA B735

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).

Time and place:
Mar. 26, 2015 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:

Modular curves V

Time and place:
Mar. 25, 2015 2:15 PM -
Mar. 23, 2015 4:00 PM,
VB, Auditorium 2

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

Time and place:
Mar. 25, 2015 1:00 PM - 3:00 PM,
"bikuben" - Kristine Bonnevies hus

Time and place:
Mar. 25, 2015 12:00 PM - 2:30 PM,
Nuklus - 2+3 in Kristine Bonnevies hus (Biology building)

Time and place:
Mar. 24, 2015 12:15 PM -
Mar. 23, 2015 2:00 PM,
VB, Auditorium 2

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

Time and place:
Mar. 23, 2015 12:15 PM - 2:00 PM,
VB, Auditorium 2

These are the first two of six 45-min. lectures given by Anders Hansen (Cambridge Univ. and UiO) on Compressed sensing - Theory and Applications.

Time and place:
Mar. 19, 2015 2:15 PM - 4:00 PM,
B62, NH Abels hus

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

Modular curves IV

Time:
Mar. 17, 2015 2:15 PM

Olav Breivik (Dept. of Math., UiO ) gives a seminar in room 107, 1st floor N.H. Abels House at 14:15 March 17th: Bycatch of juvenile cod in the Barents Sea shrimp fishery

Time and place:
Mar. 13, 2015 2:30 PM - 3:30 PM,
NHA rest area

*Abstract: **In this talk I briefly review the connection between these two areas **and describe basic structures and problems underlying both fields.*

Coffee/tea and cookies will be served from 14.00 to 14.30.

Time and place:
Mar. 12, 2015 2:15 PM - 4:00 PM,
B62, NH Abels hus

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

Modular curves III

Time and place:
Mar. 12, 2015 10:15 AM - 12:00 PM,
Ole Johan Dahls hus, møterommet i etasje 9

Sam Sanders, Ghent and Munich, will give a lecture with the tittle

On the contingency of predicativism.