Arrangementer - Side 2

Tid og sted: 20. des. 2017 10:15, Rom "Hurricane" på Ullevål, Sognsveien 77 B


Representations of Cuntz–Krieger Algebras and Wavelets on Fractals


Tid og sted: 19. des. 2017 14:00 - 15:00, Desolation row, Ullevål

Antoine Julien, Universitetet i Nord, will give a talk with title:  Rieffel-type projections in higher-dimensional rotation algebras

Abstract: Rieffel first built a non-trivial projection in the rotation algebra by considering a certain C*-module over this algebra, and exploiting the Morita equivalence which it implements. In this talk, I will present how it is possible to extend these ideas to construct explicitly projections in higher-dimensional noncommutative tori. Precisely, our techniques can be applied to the NC tori which are associated with an R^d-flow on a 2d-torus, or equivalently which are given by the crossed product of C(T^d) by Z^d. I will also hint on how this result can be interpreted as constructing Gabor atoms associated with some lattices in the time-frequency space R^{2d}. This is a joint work with Franz Luef (NTNU).

Tid og sted: 15. des. 2017 13:00, Rom "Hurricane", Ullevål, Sognsveien 77 B


The Cone Conjecture for Some Calabi-Yau Varieties


Tid og sted: 13. des. 2017 13:15, Ullevål Stadion: Gates of Eden

M.Sc. Hannes Hagen Haferkorn ved Matematisk institutt vil forsvare sin avhandling for graden ph.d.:

The effect of noise in the modelling and the analysis of random systems


Tid og sted: 13. des. 2017 11:00 - 12:00, Desolation Row, Sognsv. 77B

Abstract: Recently, Steve Kaliszewski, Tron Omland, and I have been investigating the following theorem of Pedersen: two actions of a compact abelian group on C*-algebras A and B are outer conjugate if and only if there is an equivariant isomorphism between the crossed products that respects the positions of A and B. We upgraded this to nonabelian groups (using coactions on the crossed products), and then searched for examples showing that the last condition (on the positions of A and B) is necessary. We failed. This lead us to formulate the "Pedersen Rigidity Problem": if the crossed products of A and B are equivariantly isomorphic, are the actions on A and B outer conjugate? We have been finding numerous "no-go theorems", which give various sufficient conditions for Pedersen Rigidity. Quite recently we have done this for ergodic actions of a compact group, assuming that the actions have "full spectrum". In fact, these actions are (not just outer) conjugate if and only if the dual coactions are. I will summarize our progress on the Pedersen Rigidity Problem and outline the proof of the no-go theorem for these compact ergodic full-spectrum actions.

Tid og sted: 13. des. 2017 10:15, Gates of Eden, Ullevål stadion

M.Sc. Hannes Hagen Haferkorn ved Matematisk institutt avholder prøveforelesning over oppgitt emne: "Harmonic functions, Brownian motion and martingales".

Tid og sted: 12. des. 2017 13:00, Rom "End of the Line", Sognsveien 77 B.


Transfinite surface interpolation over irregular n-sided domains


Tid og sted: 12. des. 2017 09:00, Fysikkbygningen: Kristian Birkelands auditorium


Time Evolution of Quantum Mechanical Many-Body Systems


Tid og sted: 11. des. 2017 13:30, Rom "End of the Line" på Ullevål, Sognsveien 77 B.


Fiducial and Objective Bayesian Inference


Tid og sted: 11. des. 2017 10:00, Rom "End of the Line" på Ullevål, Sognsveien 77 B.


Topics in Condence Distributions

Tid og sted: 7. des. 2017 10:30, Rom "Desolation Row", Ullevål, Sognsveien 77 B


American Options in Financial Quotes

Tid og sted: 7. des. 2017 10:30, Møterom "End of the Line", Ullevål, Sognsveien 77 b


Comparison of two lower bounds for availabilities in multistate monotone systems -an established one and a new one

Tid og sted: 4. des. 2017 09:00 - 8. des. 2017 12:00, Room 108, N.H. Abel's House
Tid og sted: 30. nov. 2017 14:30 - 15:30, Gates of Eden, Sognsv. 77B


NB! Coffee/Tea/Biscuits from 14.00.

Tid og sted: 29. nov. 2017 09:00 - 10:00, Seminarrom 108

Eksamenstiden nærmer seg med stormskritt! Hvordan går det? Kom og få gratis kaffe og mat på seminarrom 108. Det blir julestemning! / The exam period is ahead! How are you really? Come to the seminar room 108 and get free coffee and food. You can look forward to Christmas atmosphere!

Tid og sted: 24. nov. 2017 13:15, Ullevål Stadion: Gates of Eden

M.Sc. Espen Stokkereit ved Matematisk institutt vil forsvare sin avhandling for graden ph.d.:

Essays on Stochastic Optimal Stopping and Control


Tid: 24. nov. 2017 11:30 - 12:00

Andreas Carlson og Jean Rabault

Nature has invented ingenious aerodynamic design solutions, some of which are critical for plants as wind dispersal of seeds and fruits is coupled to their flight performance. This formulates into an optimization problem for plants: large seed wings can lead to increased lift and more efficient dispersion, but are costly for the tree to build and can more easily be trapped in the canopy. Double winged seeds/fruits separate from their tree when a specific level of dessication is reached, and autorotate as they descend to the ground. This leads to the question: how is the wing curvature of seeds/fruits linked to their flight performance? To answer this, we develop a theoretical model that suggests the existence of an optimal wing curvature that yields maximal lift. To further understand the interplay between the flow and the wing geometry, we perform a synthetic seed adaptation by deploying 3D printing of double winged fruits that we use in flight experiments, where we span the phase space of aerial dynamics by changing the of wing curvature and seed/fruit weight. Experiments confirm that there is a sweet-spot in curvature to maximise the flight time consisted with geometrical measurements from a wide range of seeds in Nature. Our results highlights the importance of not curving too much or too little for helicopter fruits to have an optimal flight performance.

Tid: 24. nov. 2017 11:00 - 11:30

Elisabeth Seland

In my job as research adviser, I receive a lot of questions about rights, possibilities and problems in connection with scientific publishing and open access. Both EU and the Norwegian Research Council have rules about this, and there is also a UiO policy in place that is relevant for all employees. I will give a short presentation to try to clear up what you have to, must, may, could and should related to Open access. In my experience many of you have the same questions about these issues, so I hope you bring your questions with you and we can address them in the seminar.

Tid og sted: 22. nov. 2017 14:15 - 16:00, Desolation Row, Sognsveien 77 B

I will discuss the differential structure in the mod 2 Adams spectral sequence for tmf, leading to its E_\infty-term.  These calculations were known to Hopkins-Mahowald; in their current guise they are part of joint work with Bruner.

Tid og sted: 20. nov. 2017 10:00, Seminarrom End of the Line, Ullevål stadion, Sognsveien 77 B


Pricing of Spreads and Other Options in Cointegrated Markets

Tid og sted: 15. nov. 2017 14:30 - 16:00, Desolation Row, Sognveien 77 B

I will report on work in progress on calculations of the motivic homotopy groups of MGL (the algebraic cobordism spectrum) over number fields. It is known that pi_{2n,n}(MGL) is the Lazard ring, and pi_{-n,-n}(MGL) is Milnor K-theory of the base field. We will calculate all of pi_{*,*}(MGL) with the slice spectral sequence (motivic Atiyah-Hirzebruch spectral sequence) over a number field. I will give a brief review of the the tools and sketch the main parts of the calculation: The input from motivic cohomology, the use of C_2-equivariant Betti realization and comparison with Hill-Hopkins-Ravenel to determine the differentials, and settle most of the hidden extensions. 

Tid og sted: 8. nov. 2017 15:00 - 16:00, Hurricane, Sognsveien 77 b

I will discuss the algebra structure of the E_2-term of the mod 2 Adams spectral sequence for tmf, given by the cohomology Ext_{A(2)}(F_2, F_2) of A(2).  We (Bruner & Rognes) use Groebner bases to verify the presentation given by Iwai and Shimada, with 13 generators and 54 relations. Thereafter I will discuss the relationship between differentials and Steenrod operations in the Adams spectral sequence for E_\infty ring spectra.  

Tid og sted: 8. nov. 2017 13:15, Ullevål Stadion: Gates of Eden

M.Sc. Fredrik Meyer ved Matematisk institutt vil forsvare sin avhandling for graden ph.d.:

Join of hexagons and Calabi–Yau threefolds


Welcome to the second FINEWSTOCH Networkshop. The workshop will bring together leading researchers in stochastics and probability theory to discuss recent developments with a particular focus on finance, insurance, energy and weather. 

Tid og sted: 8. nov. 2017 10:15, Gates of Eden, Ullevål stadion

M.Sc. Fredrik Meyer ved Matematisk institutt avholder prøveforelesning over oppgitt emne: "Prym varieties: basic constructions and central results".