## Visiting address

Niels Henrik Abels husMoltke Moes vei 35 (map)

0851 OSLO

Norway

Time and place:
Oct. 9, 2015 1:15 PM,
Aud. 5 Vilhelm Bjerknes' hus

M.Sc. Zhaochu Yang ved Matematisk institutt vil forsvare sin avhandling for graden ph.d.: *Microfluidic sensing and power generation with coplanar interdigital capacitors*

Time and place:
Oct. 9, 2015 10:15 AM,
Aud. 5 Vilhelm Bjerknes' hus

M.Sc. Zhaochu Yang ved Matematisk institutt avholder prøveforelesning over oppgitt emne: "State of the art and prospects of wearable microsystems technologies".

Time and place:
Oct. 6, 2015 12:15 PM - 1:00 PM,
NHA 935

Mathematical Institute, University of Oxford

Time and place:
Oct. 1, 2015 2:15 PM - 4:00 PM,
B738, NH Abels hus

Martin Gulbrandsen, UiS, gives the Seminar in Algebra and Algebraic Geometry

The dual cell complex of Hilbert scheme degenerations

Time and place:
Sep. 30, 2015 2:15 PM - 4:00 PM,
B738

Judith Packer, University of Colorado (Boulder), USA, will give a talk with title: Wavelets associated to representations of higher-rank graph C*-algebras

Abstract: Let $\Lambda$ denote a finite $k$-graph in the sense of A. Kumjian and D. Pask that is strongly connected, and let $\Lambda^{\infty}$ denote its infinite path space. I discuss some recent joint work with C. Farsi, E. Gillaspy, and S. Kang, where we construct a system of functions that we call ``wavelets" on a Hilbert space of square-integrable functions on $\Lambda^{\infty}.$ In so doing, we generalize work of M. Marcolli and A. Paolucci for finite directed graphs to the higher rank case. The key tool is the construction of a representation of the graph $C^*$-algebra $C^{\ast}(\Lambda)$ on $L^2(\Lambda^{\infty},M)$ for the appropriate measure $M.$ When the finite $k$-graph $\Lambda$ in question is strongly connected and aperiodic, the representation of $C^{\ast}(\Lambda)$ that we obtain is faithful.

Time and place:
Sep. 29, 2015 2:45 PM,
Lunch area

Fabian Krüger (Heidelberg Institute for Theoretical Studies) will give a 30 min seminar in the lunch area, 8th floor N.H. Abel's House at 14:45 September 29th.

Time and place:
Sep. 29, 2015 2:15 PM,
Lunch area 8th floor, NHA

Monica Musio (University of Cagliari) will give a 30 min seminar in the lunch area, 8th floor N.H. Abel's House at 14:15 September 29th.

Time and place:
Sep. 25, 2015 10:15 AM - 12:00 PM,
B 735

Antoine Julien, NTNU, will give a talk with title: Links between cut-and-project tilings and Diophantine approximation

Abstract: Cut-and-project tilings are obtained by cutting a slice of a higher dimensional lattice and projecting it on a lower dimensional space. The result is a point set which is regular enough (since it originates from a lattice), but is not periodic, provided the direction of the slice is irrational in a suitable sense. In one dimension, typical examples of this construction are Sturmian subshifts. It is known that some of their dynamical properties depend on the arithmetic properties of a certain parameter. In this talk, I will recall some known results by Hedlund and Morse on Sturmian subshifts. Then, I will describe how, even in higher dimensions, the repetition properties of some cut-and-project sets can be linked to problems of simultaneous Diophantine approximation. This is joint work with A. Haynes, H. Koivusalo and J. Walton.

Time and place:
Sep. 24, 2015 2:15 PM - 4:00 PM,
B738, NH Abels hus

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

EPW cubes

Time and place:
Sep. 17, 2015 2:15 PM - 4:00 PM,
B738, NH Abels hus

Felipe Rincon, UiO, gives the Seminar in Algebra and Algebraic Geometry

Positroids and the totally nonnegative Grassmannian

Time and place:
Sep. 15, 2015 2:15 PM,
Lunch area, 8th floor N.H. Abel's House

Audun Mathias Øygard (Master student, Dept. of Mathematics, UiO) will give a seminar in the lunch area, 8th floor N.H. Abel's House at 14:15 September 15th: Measuring similarity of classified advertisements using images and text, with applications to recommendation and search at finn.no

Time and place:
Sep. 11, 2015 2:30 PM - 3:30 PM,
Rest area 7 th. floor NHA

Abstract; Grassmannians and flag varieties play fundamental role in modern mathematics. They show up in many different situations and have been extensively studied from the point of view of algebraic geometry, topology,representation theory and combinatorics. In the first part of my talk I will recall the main properties of the Grassmannians and flag varieties. In particular, I will describe the connection with the representation theory of the general linear group. In the second part of the talk I will describe recent results on the Poincaré–Birkhoff–Witt degenerations. The main idea to be utilized is the connection between the representation spaces and the varieties we are interested in.

Coffee/Tea/Biscuits from 14.00

Time and place:
Sep. 10, 2015 2:15 PM - 4:00 PM,
B738, NH Abels hus

Felipe Rincon, UiO, gives the Seminar in Algebra and Algebraic Geometry

Tropical Ideals

Time and place:
Sep. 4, 2015 1:15 PM,
Aud. 5 Vilhelm Bjerknes' hus

M. Sc. David Ruiz Baños ved Matematisk institutt vil forsvare sin avhandling for graden ph.d.:

Regularity of Stochastic Flows of Stochastic Differential Equations with Singular Coefficients and Applications to Finance

Time and place:
Sep. 4, 2015 10:15 AM,
Aud. 5 Vilhelm Bjerknes' hus

M.Sc. David Ruiz Baños ved Matematisk institutt avholder prøveforelesning over oppgitt emne: "Enlargement of filtrations and their applications".

Time and place:
Sep. 3, 2015 2:15 PM - 3:00 PM,
Niels Henrik Abels hus, room 935

Paul Krühner (TU Wien) holds a lecture with the title: Affine processes with compact state space and counter-examples for polynomial processes.

Time and place:
Sep. 2, 2015 2:15 PM - 4:00 PM,
NHA 738

Nicolai Stammeier (Münster) will give a talk with title "Aiming for accuracy - boundary quotients of right LCM semigroups revisited "

Abstract: I will recall the notions of foundation sets and the boundary quotient for right LCM semigroups. This C*-algebra is obtained by modding out products of defect projections over foundation sets in the full semigroup C*-algebra of the right LCM semigroup. Observing that this is in stark contrast to the standard presentations of C*-algebras in the spirit of Cuntz algebras, where a summation relation gets used, we will discuss the possibility of replacing the product relation by a summation relation and arrive at the accurate refinement property. This feature turns out to be quite common among right LCM semigroups. In fact, we are yet to see an example of a right LCM semigroup that has an insufficient supply of accurate foundation sets. Time permitting, we will leave the realm of right LCM semigroups for the sake of finding semigroups without the accurate refinement property.

Time and place:
Sep. 1, 2015 2:15 PM,
Room B81

Valeria Vitelli (Dept. of Biostatistics, UiO) will give a seminar in room 801 (B81), 8th floor N.H. Abels House at 14:15 September 1st: Probabilistic preference learning with the Mallows rank model

Time and place:
Aug. 28, 2015 1:15 PM,
Aud. 5 Vilhelm Bjerknes' hus

M. Sc. Jonathan Feinberg ved Matematisk institutt vil forsvare sin avhandling for graden ph.d.:

Some Improvements and Applications of Non-intrusive Polynomial Chaos Expansions

Time and place:
Aug. 28, 2015 10:15 AM,
Aud. 5 Vilhelm Bjerknes' hus

M.Sc. Jonathan Feinberg ved Matematisk institutt avholder prøveforelesning over oppgitt emne: "A critical review of numerical methods for stochastic Langevin equations".

Time and place:
Aug. 27, 2015 2:15 PM - 4:00 PM,
B738, NH Abels hus

Felipe Rincon, UiO, gives the Seminar in Algebra and Algebraic Geometry

An introduction to tropical geometry

Time and place:
Aug. 26, 2015 3:00 PM - 4:00 PM,
Niels Henrik Abels hus, room 1036

Andrey Pilipenko (Ukrainian National Academy of Sciences) gives a lecture with the title: Limits of Markov processes with irregular behavior at a fixed point.

Time and place:
Aug. 24, 2015 1:15 PM - 2:00 PM,
Niels Henrik Abels hus, room 108

Tijana Levajkovic (University of Innsbruck) holds a lecture with the title: Chaos expansions for stochastic evolution equations.

Time and place:
Aug. 7, 2015 8:00 PM -
Aug. 11, 2015 6:45 AM,
Coastal Express (Hurtigruten), Norway

Please note that participation is by invitation only. Note also that there is an official homepage of the Abel Symposium 2015.

The Abel Symposium is administrated by the Norwegian Mathematical Society.

Time and place:
June 26, 2015 1:15 PM,
Aud. 5 Vilhelm Bjerknes' hus

M.Sci Franziska Weber ved Matematisk institutt vil forsvare sin avhandling for graden ph.d.:

Convergent Numerical Methods for Nonlinear Partial Differential Equations