Tidligere arrangementer - Side 90
Join us on PharmaTox open seminar series.
Attendance is free and open for everybody. Registration is required.
ESOP organises a workshop on learning in social situations as part of a two-day event marking the end of the centre's CoE-period.
How can we break the vicious cycle of increasing inequality and social unrest in the world today? Is there a future for society models with low inequality and high productivity?
27. oktober arrangeres et seminar i samfunnsfarmasi for ? markere professor Else-Lydia Toveruds verdifulle innsats for farmasien gjennom mange ?r.
Given a Nisnevich sheaf (on smooth schemes of finite type) of spectra, there exists a universal process of making it ?1-invariant, called ?1-localization. Unfortunately, this is not a stalkwise process and the property of being stalkwise a connective spectrum may be destroyed. However, the ?1-connectivity theorem of Morel shows that this is not the case when working over a field. We report on joint work with Johannes Schmidt and sketch our approach towards the following theorem: Over a Dedekind scheme with infinite residue fields, ?1-localization decreases the stalkwise connectivity by at most one. As in Morel’s case, we use a strong geometric input which is a Nisnevich-local version of Gabber’s geometric presentation result over a henselian discrete valuation ring with infinite residue field.
The advances on the Milnor- and Bloch-Kato conjectures have led to a good understanding of motivic cohomology and algebraic K-theory with finite coefficients. However, important questions remain about rational motivic cohomology and algebraic K-theory, including the Beilinson-Soulé vanishing conjecture. We discuss how the speaker's "connectivity conjecture" for the stable rank filtration of algebraic K-theory leads to the construction of chain complexes whose cohomology groups may compute rational motivic cohomology, and simultaneously satisfy the vanishing conjecture. These "rank complexes" serve a similar purpose as Goncharov's candidates for motivic complexes, but have the advantage that they have a precise relation to rational algebraic K-theory.
Tone Bratteteig, Professor - Research Group for Design of Information Systems
The so-called Koras-Russell threefolds are a family of topologically
contractible rational smooth complex affine threefolds which played an
important role in the linearization problem for multiplicative group
actions on the affine 3-space. They are known to be all diffeomorphic to
the 6-dimensional Euclidean space, but it was shown by Makar-Limanov in
the nineties that none of them are algebraically isomorphic to the affine
3-space. It is however not known whether they are stably isomorphic or not
to an affine space. Recently, Hoyois, Krishna and ?stv?r proved that many
of these varieties become contractible in the unstable A^1-homotopy
category of Morel and Voevodsky after some finite suspension with the
pointed projective line. In this talk, I will explain how additional
geometric properties related to additive group actions on such varieties
allow to conclude that a large class of them are actually A^1-contractible
(Joint work with Jean Fasel, Université Grenoble-Alpes).
By Malin Pinsky from Rutgers University, United States
Tomi Koivisto, NORDITA
Digital signalbehandling og bildeanalyse, UiO and PGS
The effects of moving rough sea surfaces on seismic data.
Andreas Andersson (UiO): An introduction to duality for compact groups in algebraic quantum field theory
Tamara Broderick (Massachusetts Institute of Technology) will give a seminar in the lunch area, 8th floor Niels Henrik Abels hus at 14:15.
In this talk, we will present some applications of the "transfer" to
algebraic K-theory, inspired by the work of Thomason. Let A --> B be a
G-Galois extension of rings, or more generally of E-infinity ring spectra
in the sense of Rognes. A basic question in algebraic K-theory asks how
close the map K(A) --> K(B)^hG is to being an equivalence, i.e., how close
K is to satisfying Galois descent. Motivated by the classical descent
theorem of Thomason, one also expects such a result after "periodic"
localization. We formulate and prove a general lemma that enables one to
translate rational descent statements as above into descent statements
after telescopic localization. As a result, we prove various descent
results in the telescopically localized K-theory, TC, etc. of ring
spectra, and verify several cases of a conjecture of Ausoni-Rognes. This
is joint work with Dustin Clausen, Niko Naumann, and Justin Noel.
ESOP seminar. Johannes Urpelainen is Associate Professor at Columbia University. He will present his paper "Electoral Backlash or Positive Reinforcement? Wind Power and Congressional Elections in the United States", written jointly with Alice Tianbo Zhang.
Morten Bo Madsen, Associate Professor, Astrophysics and Planetary Science, Niels Bohr Institute
The Bass-Quillen conjecture states that every vector bundle over A^n_R is
extended from Spec(R) for a regular noetherian ring R. In 1981, Lindel
proved that this conjecture has an affirmative solution when R is
essentially of finite type over a field. We will discuss an equivariant
version of this conjecture for the action of a reductive group. When R =
C, this is called the equivariant Serre problem and has been studied by
authors like Knop, Kraft-Schwarz, Masuda-Moser-Jauslin-Petrie. In this
talk, we will be interested in the case when R is a more general regular
ring. This is based on joint work with Amalendu Krishna
Michal Michalowski, Royal Observatory Edinburgh, School of Physics and Astronomy, The University of Edinburgh
Enrico Fermi and the birth of modern nonlinear physics
In the early fifties in Los Alamos E. Fermi in collaboration with J. Pasta and S. Ulam investigated a one dimensional chain of equal masses connected by a weakly nonlinear spring. The key question was related to the understanding of the phenomenon of conduction in solids; in particular they wanted to estimate the time needed to reach a statistical equilibrium state characterized by the equipartition of energy among the Fourier modes. They approached the problem numerically using the MANIAC I computer; however, the system did not thermailize and they observed a recurrence to the initial state (this is known as the FPU-recurrence). This unexpected result has led to the development of the modern nonlinear physics (discovery of solitons and integrability). In this seminar, I will give an historical overview of the subject and present the different approaches that have been proposed in the last 60 years for explaining this paradox. Very recent results on the estimation of the time scale and on the explanation of the mechanism of equipartition will also be discussed.
In Part 2 we will delve into the worlds of derived and spectral algebraic
geometry. After reviewing some basic notions we will explain how motivic
homotopy theory can be extended to these settings. As far as time permits
we will then discuss applications to virtual fundamental classes, as well
as a new cohomology theory for commutative ring spectra, a brave new
analogue of Weibel's KH
In Part 2 we will delve into the worlds of derived and spectral algebraic
geometry. After reviewing some basic notions we will explain how motivic
homotopy theory can be extended to these settings. As far as time permits
we will then discuss applications to virtual fundamental classes, as well
as a new cohomology theory for commutative ring spectra, a brave new
analogue of Weibel's KH