Tidligere arrangementer - Side 93

We consider extensions of Morel-Voevodsky's motivic homotopy theory to the

settings of derived and spectral algebraic geometry. Part I will be a

review of the language of infinity-categories and the setup of

Morel-Voevodsky homotopy theory in this language. As an example we will

sketch an infinity-categorical proof of the representability of Weibel's

homotopy invariant K-theory in the motivic homotopy category.

Numerical methods for stochastic conservation laws

Friday seminar by Marcin Piwczy¨½ski from Nicolaus Copernicus University in Toru¨½, Poland

Nick Kaiser, IfA, Hawai University

Experimental investigation of linear stability mechanisms in stratified gas-liquid pipe flow

The evolution of interfacial waves on a stratified air water pipe flow is investigated experimentally. An oscillating plate introduced controlled perturbations at the inlet of the pipe. High speed cameras captured the evolution of these perturbations along the pipe by means of a phase-locked shadowgraphy technique. Thereby, it was possible to measure the temporal and the spatial evolution of the disturbances introduced in the flow. Particle image velocimetry was performed further downstream in order to evaluate changes in the base flow. 

A relatively large data bank has been gathered with varying air and water flow rates as well as varying amplitudes and frequencies of the inlet perturbations. Some preliminary results contain a qualitative assessment of linear vs. non-linear regimes and momentum transfer into the water layer.

Professor Eric Priest, St Andrews University, Scotland:

Our Dynamic Sun

Yuan Wang (Utah), gives the Seminar in Algebra and Algebraic Geometry:

"On the characterization of abelian varieties for log pairs in zero and positive characteristic"

Eric Priest, University of St.Andrews

H?vard Kvamme (UiO, Dept. of mathematics) will give a seminar in the lunch area, 8th floor Niels Henrik Abels hus at 14:15.

We will discuss the motivic May spectral sequence and demonstrate how to  use it to identify Massey products in the motivic Adams spectral sequence.  We will then investigate what is known about the motivic homotopy groups  of the eta-local sphere over the complex numbers and discuss how these  calculations may work over other base fields.  

Jack Carlyle, ITA, Postdoc

Francesco Galuppi (UiO/Ferrara) gives the algebraic geometry seminar:

"Identifiability of polynomials and Cremona transformations."

Genetic and environmental pathways to substance use and misuse.

Alfredo Galindo-Uribarri, Oak Ridge National Laboratory / University of Tennessee, Knoxville.

Certain 3-dimensional lens spaces are known to smoothly bound 4-manifolds with the rational homology of a ball. These can sometimes be useful in cut-and-paste constructions of interesting (exotic) smooth 4-manifolds. To this end it is interesting to identify 4-manifolds which contain these rational balls. Khodorovskiy used Kirby calculus to exhibit embeddings of rational balls in certain linear plumbed 4-manifolds, and recently Park-Park-Shin used methods from the minimal model program in 3-dimensional complex algebraic geometry to generalise Khodorovskiy's result. The goal of this talk is to give an accessible introduction to the objects mentioned above and also to describe a much easier topological proof of Park-Park-Shin's theorem.  

Bartosz Kwasniewski (Odense) will give a talk with title: Paradoxicality and pure infiniteness of  C*-algebras associated to Fell bundles

Abstract: Abstract: In this talk we present conditions implying  pure infiniteness of the reduced cross-sectional $C^*$-algebra $C^*_r(\mathcal{B})$ of a Fell bundle $\mathcal{B}$ over a discrete group $G$. We introduce notions of aperiodicity, $\mathcal{B}$-paradoxicality and  residual $\mathcal{B}$-infiniteness.  We discuss their relationship with similar conditions studied, in the context of crossed products, by the following duos: Laca, Spielberg; Jolissaint, Robertson; Sierakowski, R{\o}rdam;  Giordano, Sierakowski and Kirchberg, Sierakowski.    (based on  joint work with Wojciech Szyma{\'n}ski)

Francesca Biagini, professor in mathematical finance from Ludwig-Maximillian University of Munich, will give an intensive course from Tuesday Sept 13 to Friday Sept 16.

By Jukka Corander 

Ata karakci, Postdoctoral Researcher , ITA

Seckin Adali (UiO), gives the Seminar in Algebra and Algebraic Geometry:

Singularities of Restriction Varieties in OG(k,n)

In the nineties, Deninger gave a detailed description of a conjectural cohomological interpretation of the (completed) Hasse-Weil zeta function of a regular scheme proper over the ring of rational integers. He envisioned the cohomology theory to take values in countably infinite dimensional complex vector spaces and the zeta function to emerge as the regularized determinant of the infinitesimal generator of a Frobenius flow. In this talk, I will explain that for a scheme smooth and proper over a finite field, the desired cohomology theory naturally appears from the Tate cohomology of the action by the circle group on the topological Hochschild homology of the scheme in question.  

Abstract: Exploring connections between subfactors and conformal field theories, Vaughan Jones recently observed that planar algebras give rise to unitary representations of the Thompson group F, and more generally,  to unitary representations of the group of fractions of certain categories. Remarkably, this procedure applies to oriented link invariants. In particular, a suitably normalized HOMFLYPT polynomial is a positive definite function on the oriented Thompson group. (Based on joint work with V. Aiello and V. Jones.)

The motivic Adams spectral sequence is a general tool for calculating homotopy groups of a motivic spectrum X. We will investigate the construction of the motivic Adams spectral sequence, determine the second page of the spectral sequence, and identify what it converges to in good cases. If time permits, we will show how to use the motivic Adams spectral sequence to obtain explicit calculations of the motivic homotopy groups of spheres and other spectra. 

On 5-7 September the first STORE PHD Gathering will take place, with two intensive courses. The first is on the new class of stochastic processes called Trawl processes and instructed by Almut Veraart from Imperial College London, UK. The second is led by Rudiger Kiesel from University of Duisburg-Essen, Germany, and focuses on intra-day trading of electricity.