Tidlegare arrangement - Side 295
Tommaso Dorigo, INFN Padua
The CDF collaboration led for two decades the investigation of the high-energy frontier in the search for new physics at the highest energies until then achieved, provided by the Tevatron collider. In a recently published book the author describes how the experiment handled several unexplained phenomena found in the data, and the complex sociology of a large collaboration divided by different feelings on how to deal with those unexpected findings. The seminar will start by discussing the history of those anomalies and their resolution, and then focus on the statistical problem of defining a proper discovery level for new phenomena and on the non-trivial issues it entails.
Jan F. Evensen, OUS/Radiumhospitalet
Late Lunch Talk by Sergio Magallanes Argany, University of Extremadura
Given a Nisnevich sheaf (on smooth schemes of finite type) of spectra, there exists a universal process of making it 𝔸1-invariant, called 𝔸1-localization. Unfortunately, this is not a stalkwise process and the property of being stalkwise a connective spectrum may be destroyed. However, the 𝔸1-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, 𝔸1-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.
Thomas Schellenberger at the Department of Geosciences will be defending his dissertation: Analysis of glacier surface velocity using repeat Synthetic Aperture Radar (SAR) images
Tone Bratteteig, Professor - Research Group for Design of Information Systems
This Friday we'll discuss a paper from the future American Naturalist presenting a new tool; "Phylogenetic ANCOVA: Estimating Changes in Evolutionary Rates as Well as Relationships between Traits" by Fuentes-G., Housworth, Weber and Martins.
Join in!
Isolation and Characterization of Cancer-Derived Exosomes
Sebastian Wild, DESY Hamburg
One of the most promising strategies to probe WIMP dark matter is direct detection, i.e. the search for nuclear recoils produced by the elastic scattering of dark matter particles. After giving a general introduction to the theoretical framework and experimental status of direct detection, I will present recent developments which allow to interpret the experimental data without the need to specify the (unknown) velocity distribution of dark matter, called "halo-independent methods". Specifically, I will discuss to what extent future experiments can pinpoint the particle physics properties of dark matter in a halo-independent way. I will also present a novel approach to derive upper limits on the scattering cross section of dark matter using already existing experiments, again without the need to specify the velocity distribution.
(The slides will be available here)
Eirik Malinen, Department of Physics, UiO
MD. Edem Kwame Kossi at the Department of Informatics will be defending his dissertation for the degree of Ph.D:
Bottom-up Architecting of National and Regional Health Information Systems in Malawi and West Africa
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 Østvær 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
Master i fysikk Kyrre Ness Sjøbæk ved Fysisk institutt vil forsvare sin avhandling for graden ph.d: "Avoiding vacuum arcs in high gradient normal conducting RF structures."
Tomi Koivisto, NORDITA
Digital signalbehandling og bildeanalyse, UiO and PGS
The effects of moving rough sea surfaces on seismic data.
Master i fysikk Kyrre Ness Sjøbæk ved Fysisk institutt avholder prøveforelesning over oppgitt emne: ""Medical applications of particle Accelerators"
Nina Frederike Jeppesen Edin, Department of Physics, UiO
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.
Late Lunch Talk by Joost Raeymaekers, Centre for Biodiversity Dynamics, NTNU
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.