Tidligere arrangementer - Side 91

Speaker: Vadim Makarov. Institute for Quantum Computing, University of Waterloo, Canada.

Abstract: We first discuss C*-simplicity and the unique trace property for discrete groups in light of recent years' development. In particular, we consider amalgamated free products, and give conditions for such to be (and fail to be) C*-simple. Then we define radical and residual classes of groups, and explain that there exists a radical detecting C*-simplicity, in a similar way as the amenable radical detects the unique trace property. The talk is based on joint work with Nikolay A. Ivanov from Sofia University, Bulgaria.

Hopkins, Kuhn, and Ravenel proved that, up to torsion, the Borel-equivariant  cohomology of a G-space with coefficients in a height n-Morava E-theory is  determined by its values on those abelian subgroups of G which are generated by  n or fewer elements. When n=1, this is closely related to Artin's induction  theorem for complex group representations. I will explain how to generalize the  HKR result in two directions. First, we will establish the existence of a  spectral sequence calculating the integral Borel-equivariant cohomology whose  convergence properties imply the HKR theorem. Second, we will replace Morava  E-theory with any L_n-local spectrum. Moreover, we can show, in some sense, a  partial converse to this result: if an HKR style theorem holds for an E_\infty  ring spectrum E, then K(n+j)_* E=0 for all j\geq 1. This partial converse has  applications to the algebraic K-theory of structured ring spectra.  

Scientific lecture by Dr. Jesmond Dalli, Sir Henry Dale Fellow and QMUL Lipid Mediator Unit Director at the Barts and The London School of Medicine and Dentistry, Queen Mary University of London.

By Jaap A. Kaandorp from University of Amsterdam

Peter M¨¹ller (University of Texas at Austin) will give a seminar in the lunch area, 8th floor Niels Henrik Abels hus at 14:15.

We compute the generalized slices (as defined by Spitzweck-?stv?r) of the motivic spectrum KQ in terms of motivic cohomology and generalized motivic cohomology, obtaining good agreement with the situation in classical topology and the results predicted by Markett-Schlichting.  

Bridget Falck, Postodoctoral fellow ITA

Kristina Rognlien Dahl (University of Oslo) is giving her inaugural lecture with the title: Stochastic analysis meets risk and reliability theory.

Rajeev Bhaskaran (Indian Statistical Institute, Bangalore, India) gives a lecture with the title: On the connection between SPDE¡¯s and diffusions arising out of an SDE.

Michael Whittaker from University of Glasgow will give a talk with title:  New directions in self-similar group theory

Abstract: A self-similar group (G,X) consists of a group G acting faithfully on a homogeneous rooted tree such that the action satisfies a self-similar condition. In this talk I will generalise the above definition to faithful groupoid actions on the path space of more general graphs. This new definition allows us to work out the structure of the KMS state space of associated Toeplitz and Cuntz-Pimsner algebras. This is joint work with Marcelo Laca, Iain Raeburn, and Jacqui Ramagge.  

Links Between Anger and Pain: The Role of Endogenous Opioids.

Rasmus Bryder (University of Copenhagen) will give a talk with title: Twisted crossed products over C*-simple groups

Abstract: A twisted C*-dynamical system consists of a C*-algebra, a discrete group and a "twisted" action of the group on the C*-algebra, i.e., the group acts by automorphisms on the C*-algebra in a manner determined by a 2-cocycle of the group into the unitary group of the C*-algebra. Whenever the 2-cocycle (or twist) is trivial, the action is given by a group homomorphism of the group into the automorphism group of the C*-algebra. We consider twisted C*-dynamical systems over C*-simple groups (i.e.,groups whose reduced group C*-algebra is simple) and how C*-simplicity affects the ideal structure of reduced crossed products over such dynamical systems.  

By Oscar Puebla from the GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany

Iker S. Requerey, IAC, Spain

Microfluidics of sugar transport in plants

Plants can rightly be called masters of microengineering. Their survival and successful reproduction depends on their ability to overcome a series of physical challenges during growth and when transporting matter over great distances. In this talk, we focus on the microfluidic network responsible for energy distribution (the phloem). We combine experiments on living plants and biomimetic microfluidic devices to elucidate the basic physical principles that govern sugar transport in plants. We derive a scaling relation between the characteristic sizes of the plant organs, which optimizes the rate of sugar transport. Comparison with experimental data suggests that the pipe network is operating at or near the theoretical optimum. We further consider the coupling between photosynthesis and long-distance transport. While sap with high sugar concentration has the greatest transport potential, viscosity impedes flow, a phenomena analogous to congestion in traffic flows. The optimal sugar concentration for transport in plants is 25%, sweeter than Coke (10%) but much less viscous than maple syrup (65%). Although plants have generally evolved towards the theoretical optimum, a number of unusually sweet plants exist. This group consists primarily of crop plants such as corn (40%) and potato (50%), sugar junkies of the natural world.

Dr Perrine Geraudie, Akvaplan Niva