Arrangementer

M.Sc. Torkel Andreas Haufmann ved Matematisk institutt vil forsvare sin avhandling for graden ph.d.:

Some topics in combinatorial matrix theory and on the k-regular induced subgraph problem

Du er halvveis i semesteret! Hvordan går det? Kom og få gratis kaffe og mat på seminarrom 108 / You are halfway through the semester! How are you? Come and get free coffee and food in the seminar room 108

Waldhausen's algebraic K-theory of spaces is an extension of algebraic K-theory from rings to spaces (or ring spectra) which also encodes important geometric information about manifolds. Bivariant A-theory is a bivariant extension of algebraic K-theory from spaces to fibrations of spaces. In this talk, I will first recall the definition and basic properties of bivariant A-theory and the A-theory Euler characteristic of Dwyer-Weiss-Williams. I will then introduce a bivariant version of the cobordism category and explain how this may be regarded as a universal space for the definition of additive characteristic classes of smooth bundles. Lastly, I will introduce a bivariant extension of the Dwyer-Weiss-Williams characteristic and discuss the Dwyer-Weiss-Williams smooth index theorem in this context. Time permitting, I will also discuss some ongoing related work on the cobordism category of h-cobordisms. This is joint work with W. Steimle.  

M.Sc. Rune Vegard Skullerud Fjellbo ved Matematisk institutt vil forsvare sin avhandling for graden ph.d.:

Non-singular simplicial sets

M.Sc. Torkel Andreas Haufmann ved Matematisk institutt avholder prøveforelesning over oppgitt emne: "Nonnegative factorization rank of a nonnegative matrix".

M.Sc. Rune Vegard Skullerud Fjellbo ved Matematisk institutt avholder prøveforelesning over oppgitt emne: "The s-cobordism theorem".

On Tuesday the 3rd of April there will be a presentation on the modern problems facing research data and its use. It is highly recommended that all employees at the Department of Mathematics attend.

The presentation will be held in English.

The speedskating 1000-m is a Formula One event, for the Olympics and the annual World Sprint Championships. The skaters are running in pairs, with one starting in inner lane and the other in outer lane, and then exchanging lanes on the backstretch. With speeds up to 60 km/h, there will in particular be technical challenges when negogiating the curves. Once upon a time I managed to change the Olympics, by pinpointing the statistically significant non-zero difference between last inner and last outer lane for the 500-m; the practical solution is to have the skaters running the 500-m twice, with one start in inner and one in outer. I have now properly examined the 1000-m, and found that there is a similar and in fact more dramatic Olympic Unfairness Parameter associated with that event.  

Coffee and cakes from 12.00 in the lunch room.

I will review Witt vectors, KÀhler forms and logarithmic rings, and outline how they merge in the logarithmic de Rham-Witt complex. This structure gives an algebraic underpinning for the Hesselholt-Madsen (2003) calculation of logarithmic topological cyclic homology of many discrete valuation rings.   

Er du usikker på hvilket masterstudium du vil søke på, eller bare har lyst til å høre litt mer om masterprogrammene som tilbys ved Matematisk institutt? Kom innom aud. 2 i VB (Vilhelm Bjerknes hus) 21. mars!

This talk is supposed to be an Introductionary talk to the preprint arXiv:1409.4372v4 (joint work with G.Garkusha). More specifically, using the theory of framed correspondences developed by Voevodsky, the authors introduce and study framed motives of algebraic varieties. This study gives rise to a construction of the big frame motive functor. It is shown that this functor converts the classical Morel--Voevodsky motivic stable homotopy theory into an equivalent local theory of framed bispectra, and thus producing a new approach to stable motivic homotopy theory. As a topological application, it is proved that for the simplicial set Fr(Delta^\bullet_C, S^{^1}) has the homotopy type of the space \Omega^{\infty} Sigma^{\infty} (S^{^1}). Here C is the field complex numbers. 

Tittel:

Internal models for reinsurance in Solvency II

I discuss how Bökstedt and Madsen (1994/1995) calculate mod p homotopy for THH(Z) and the fixed-point spectra THH(Z)^{C_{p^n}}, together with the R- and F-operators. This leads to a calculation for TC(Z; p) and K(Z_p), confirming the Lichtenbaum-Quillen conjecture in this case. 

I will review Bökstedt, Hesselholt and Madsen's calculations of the topological cyclic homology of prime fields and the integers, again taking into account simplifications made in later papers. (If necessary, I will continue on Thursday.)   

Recently two different refinements of Voevodsky's theory of presheaves with transfers were introduced: the first one is the theory of framed presheaves based on the unpublished notes by Voevodsky and developed by Garkusha and Panin and the second one is the theory of Milnor-Witt presheaves due to Calmes and Fasel. I will review some relations between these theories and explain that the hearts of the homotopy t-structures on the corresponding categories of motives are naturally equivalent. The talk is based on a joint work with A. Neshitov. 

Emanuela Rosazza (University of Milano Bicocca)  gives a lecture with a title: Time-consistency of risk measures: how strong is such a property?