Guest lectures and seminars

Upcoming

Time and place: June 6, 2018 9:15 AM - 4:30 PM, Hotel Bristol

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

Time and place: June 18, 2018 - June 22, 2018, Sophus Lie Conference Center, Nordfjordeid, Norway.

Nordfjordeid Summer school 2018

Time and place: Dec. 6, 2018 11:00 AM - Dec. 8, 2018 3:00 PM, University of Oslo

A conference in algebraic geometry on the occasion of Geir Ellingsrud’s 70th birthday

Previous

Time and place: May 16, 2018 12:15 PM - 2:00 PM, Vilhelm Bjerknes' House, Auditorium 2

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.

Time and place: May 15, 2018 10:15 AM - 12:00 PM, Vilhelm Bjerknes' House, Auditorium 4

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.

Time and place: May 14, 2018 12:15 PM - 2:00 PM, Vilhelm Bjerknes' House, Auditorium 2

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.

Time and place: May 9, 2018 11:15 AM - 12:00 PM, Seminar room "End of the Line"
Time and place: May 3, 2018 1:00 PM - 2:00 PM, Hurricane, Ullevål

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).

Time and place: May 2, 2018 2:15 PM - 4:00 PM, Gates of Eden, Sognsveien 77 B

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.

Time and place: May 2, 2018 11:20 AM - 12:00 PM, Desolation Row Sognsveien 77 B

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. ---

Time and place: May 2, 2018 10:15 AM - 11:05 AM, Desolation Row Sognsveien 77 B
Time and place: May 2, 2018 9:30 AM - May 4, 2018 4:30 PM, Auditorium 2 of the science library building Vilhelm Bjerknes' hus

The third Scandinavian Gathering Around Remarkable Discrete Mathematics

Time and place: Apr. 11, 2018 2:15 PM - 4:00 PM, Desolation Row, Sognsveien 77 B

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.  

Time and place: Apr. 11, 2018 11:15 AM - 12:00 PM, Seminar room "End of the Line"
Time and place: Mar. 21, 2018 2:15 PM - 4:00 PM, Desolation Row, Sognsveien 77 B

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.   

Time and place: Mar. 20, 2018 10:15 AM - 12:00 PM, End of the Line, Sognsveien 77 B

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. 

Time and place: Mar. 8, 2018 10:15 AM - 2:00 PM, Desolation Row Sognsveien 77 B

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. 

Time and place: Mar. 7, 2018 2:15 PM - 4:00 PM, Desolation Row, Sognsveien 77 B

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.)   

Time and place: Mar. 7, 2018 11:15 AM - 12:00 PM, Seminar room "End of the Line"
Time and place: Mar. 7, 2018 10:15 AM - 12:00 PM, Desolation Row, Sognsveien 77 B
Time and place: Mar. 6, 2018 10:15 AM - 12:00 PM, End of the Line, Sognsveien 77B

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. 

Time and place: Mar. 6, 2018 8:45 AM - 9:15 AM, Gates of Eden

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

Time and place: Mar. 6, 2018 8:30 AM - 5:30 PM, Gates of Eden

Stochastic Analysis PhD students and Post Docs will be sharing their current projects. Professors and Supervisors are all invited to attend the event.

Time and place: Mar. 2, 2018 10:00 AM - 11:30 AM, Ullevål Stadion: Desolation Row

Shiqi Song (University of Evry Val d'Esssone, France) will give a minicourse with the title: Topics on defaultable market and on default valuation

Time and place: Mar. 1, 2018 10:15 AM - 11:00 AM, Gates of Eden
Shiqi Song (University Evry Val Essonne) gives the lecture with a title: Multi-dimensional BSDEs whose terminal values are bounded and have bounded Malliavin derivatives