Operator Algebra Seminars

Seminar information archive ~10/26Next seminarFuture seminars 10/27~

Date, time & place Wednesday 16:30 - 18:00 122Room #122 (Graduate School of Math. Sci. Bldg.)

Seminar information archive

2010/06/03

16:30-18:00   Room #122 (Graduate School of Math. Sci. Bldg.)
Makoto Yamashita (Univ. Tokyo)
Fixed Points in the Stone-Cech boundary of Groups (ENGLISH)
[ Abstract ]
We discuss the class of discrete groups which admit fixed points under the adjoint action on the Stone-Cech boundary. Such groups have vanishing $L^2$-Betti numbers, and nonamenable ones fail to have property (AO).

2010/05/27

16:30-18:00   Room #128 (Graduate School of Math. Sci. Bldg.)
Catherine Oikonomides (Univ. Tokyo)
The C*-algebra of codimension one foliations which are almost without holonomy (ENGLISH)

2010/05/06

16:30-18:00   Room #128 (Graduate School of Math. Sci. Bldg.)
Makoto Yamashita (Univ. Tokyo)
Connes-Landi Deformation of Spectral Triples (ENGLISH)
[ Abstract ]
We describe a way to deform spectral triples with a 2-torus action and a real deformation parameter, motivated by deformation of manifolds after Connes-Landi. Such deformations are shown to have naturally isomorphic K-theoretic invariants independent of the deformation parameter.

2010/04/22

16:30-18:00   Room #128 (Graduate School of Math. Sci. Bldg.)
Nigel Higson (Pennsylvania State Univ.)
The Baum-Connes Conjecture and Group Representations (ENGLISH)
[ Abstract ]
The Baum-Connes conjecture asserts a sort of duality between the reduced unitary dual of a group and (a variant of) the classifying space of the group. The conjectured duality occurs at the level of K-theory. For example, for free abelian groups it amounts to a K-theoretic form of Fourier-Mukai duality. The conjecture has well-known applications in topology and geometry, but it also resonates in various ways with Lie groups and representation theory. I'll try to indicate how this comes about, and then focus on a fairly new aspect of the relationship that develops some early ideas of Mackey.

2010/02/18

16:30-18:00   Room #128 (Graduate School of Math. Sci. Bldg.)
Roberto Longo (University of Rome, Tor Vergata)
Von Neumann Algebras and Boundary Quantum Field Theory

2010/01/21

16:30-18:00   Room #128 (Graduate School of Math. Sci. Bldg.)
山下真 (東大数理)
On Subfactors Arising from Asymptotic Representations of Symmetric Groups

2010/01/19

16:30-18:00   Room #126 (Graduate School of Math. Sci. Bldg.)
高井博司 (首都大学東京)
Entire Cyclic Cohomology of Noncommutative Spheres

2010/01/14

16:30-18:00   Room #128 (Graduate School of Math. Sci. Bldg.)
Marius Junge (Univ. Illinois, Urbana-Champaign)
Applications of operator algebras in Quantum information theory

2010/01/07

16:30-18:00   Room #128 (Graduate School of Math. Sci. Bldg.)
Luc Rey-Bellet (Univ. Massachusetts)
Large deviations, Billiards, and Non-equilibrium Statistical Mechanics

2009/12/22

14:40-18:00   Room #128 (Graduate School of Math. Sci. Bldg.)
谷本溶 (Univ. Roma ``Tor Vergata'') 14:40-16:10
Symmetric representations of the group of diffeomorphisms of $\\mathbb R$
David Kerr (Texas A&M Univ.) 16:30-18:00
Topological entropy for actions of sofic groups

2009/12/17

16:30-18:00   Room #128 (Graduate School of Math. Sci. Bldg.)
佐藤康彦 (北海道大理)
Almost commuting unitaries and ${\\mathbb{Z}}^2$-action

2009/12/10

16:30-18:00   Room #128 (Graduate School of Math. Sci. Bldg.)
張欽 (東大数理)
Symmetric norms and spaces of operators modelled on a semifinite von Neumann algebra

2009/12/03

16:30-18:00   Room #128 (Graduate School of Math. Sci. Bldg.)
見村万佐人 (東大数理)
Vanishing of quasi-homomorphisms and the stable commutator
lengths on special linear groups over euclidean rings

2009/11/12

16:30-18:00   Room #128 (Graduate School of Math. Sci. Bldg.)
酒匂宏樹 (東大数理)
Recent results for amalgamated free products of type II$_1$ factors

2009/10/29

16:30-18:00   Room #128 (Graduate School of Math. Sci. Bldg.)
Robert Coquereaux (CNRS/CPT, Marseille)
Fusion graphs for Lie groups at level k and quantum symmetries

2009/10/22

16:30-18:00   Room #128 (Graduate School of Math. Sci. Bldg.)
Adam Skalski (Lancaster University)
On some questions related to Voiculescu's noncommutative topological entropy

2009/09/07

17:00-18:30   Room #056 (Graduate School of Math. Sci. Bldg.)
Marek Bozejko (University of Wroclaw)
Generalized Gaussian field, theta function of Jacobi and functor of second quantization

2009/07/23

16:30-18:00   Room #056 (Graduate School of Math. Sci. Bldg.)
Catherine Oikonomides (慶応大理工)
Cyclic cohomology and the Novikov conjecture

2009/07/16

16:30-18:00   Room #056 (Graduate School of Math. Sci. Bldg.)
Ingo Runkel (King's College London)
Algebraic structures in conformal field theory
[ Abstract ]
It turned out to be fruitful to isolate questions in CFT which can be formulated in a purely categorical fashion. The way left and right moving degrees of freedom can be combined to a consistent theory is an example of this, the relevant structure being a commutative symmetric Frobenius algebra. This is true independently of whether CFT is formulated via sewing of surfaces or nets of operator algebras. Another example is modular invariance, which has a surprising alternative formulation as a certain maximality condition.

2009/07/09

16:30-18:00   Room #056 (Graduate School of Math. Sci. Bldg.)
Mikael Pichot (東大数物連携宇宙研究機構)
Examples of groups of intermediate rank

2009/07/02

17:00-18:00   Room #056 (Graduate School of Math. Sci. Bldg.)
小沢登高 (東大数理)
Dixmier's Similarity Problem ---Littlewood and Forests--- (一般の数学者向け)

2009/06/25

16:30-18:00   Room #056 (Graduate School of Math. Sci. Bldg.)
鈴木章斗 (九州大学数理学研究院)
Infrared divergence of scalar quantum field model on pseudo Riemann manifold

2009/06/18

16:30-18:00   Room #056 (Graduate School of Math. Sci. Bldg.)
河東泰之 (東大数理)
The super Virasoro algebra and noncommutative geometry

2009/06/11

16:30-18:00   Room #056 (Graduate School of Math. Sci. Bldg.)
Chris Heunen (Radboud Universiteit Nijmegen)
A topos for algebraic quantum theory

2009/06/04

16:30-18:00   Room #056 (Graduate School of Math. Sci. Bldg.)
中神祥臣 (日本女子大)
Determinant for rectangular martices

< Previous 123456789101112131415 Next >