Events - Page 25

A seminar in the honour of Erik Bølviken at his 70’th birthday.

Kostiantyn Ralchenko (Taras Shevchenko National University of Kyiv) gives a lecture with the title: Maximum likelihood estimation for drift parameter of Gaussian process.

Yuliia Mishura (Taras Shevchenko National University of Kyiv) gives a lecture with the title: Fractional Cox-Ingersoll-Ross process and its applications to financial markets.

University of Oslo, Departement of Mathematics, 29-30 May 2018

Georg Sverdrups hus Auditorium 2

Further details see 

This is the third and last lecture by Anders C. Hansen (Cambridge Univ. and UiO) on this topic. Vegard Antun (UiO) will also contribute to the lecture.

Added June 06: Slides from the lectures are now available here.

This is the second in a series of three lectures by Anders C. Hansen (Cambridge Univ. and UiO) on this topic. Vegard Antun (UiO) will also contribute to the lectures.

Added June 06: Slides from the lectures are now available here.

This is the first in a series of three lectures by Anders C. Hansen (Cambridge Univ. and UiO) on this topic. Vegard Antun (UiO) will also contribute to the lectures.

Added June 06: Slides from the lectures are now available here.

Kurusch Ebrahimi-Fard (NTNU) will give a talk with title: Moment-cumulant relations in noncommutative probability and shuffle-exponentials

Abstract: In this talk we consider monotone, free, and boolean moment-cumulant relations from the shuffle algebra viewpoint. Cumulants are described as infinitesimal characters over a particular combinatorial Hopf algebra, which is neither commutative nor cocommutative. As a result the moment-cumulant relations can be encoded in terms of shuffle and half-shuffle exponentials. These shuffle exponentials and the corresponding logarithms permit to express monotone, free, and boolean cumulants in terms of each other using the pre-Lie Magnus expansion. If time permits we will revisit additive convolution in monotone, free and boolean probability and related aspects. Based on joint work with F. Patras (CNRS).

In this second talk I will prove the local slice theorem and give examples of applications, discuss compactness properties of instanton moduli spaces, and explain the definition and some properties of instanton homology.

In their book "Riemann-Roch Algebra", Fulton and Lang give an account of Chern classes in lambda-rings and a general version of Grothendieck's Riemann-Roch theorem. Their definition of Chern classes is based on the additive formal group law.  In work on connective K-theory, Greenlees and I have given an account of Chern classes in lambda-rings based on the multiplicative formal group law.  This account has an evident generalization to any formal group law.  The course will be an attempt to carry out Fulton and Lang's program in this more general setting.  Hoped for applications include generalizations of results relating rational lambda-modules to twisted Dirichlet characters. ---

The third Scandinavian Gathering Around Remarkable Discrete Mathematics

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.  

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.

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.   

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. 

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.)