Kyoto Operator Algebra Seminar

Organizers: Benoit COLLINS, Masaki IZUMI, Narutaka OZAWA.
Time and Location: 15:00 - 16:30 on Tuesday at RIMS 206
Seminar Description: This seminar features both research and introductory talks on topics in Operator Algebra, Noncommutative Geometry, Ergodic Theory, and Group Theory of various kinds (geometric, measure theoretic, functional analytic, etc.). The talks are informal and take between an hour and an hour and a half.
Useful Tips: How to Give a Good Colloquium. Advice on Giving Talks (Upgrade). Myths.
Memento: 2011  2012  2013  2014  2015 Spring/Summer

2015 Fall/Winter

 Sep. 08-11 Sci 3-110 Group Actions and Metric Embeddings Oct. 05-07 RIMS 111 Quantum fields and related topics Oct. 06 15:00 - 16:30 RIMS 206 Noriyoshi Sakuma (Aichi Kyoiku) Unimodality for free Lévy processes I will talk about recent developments of research of free infinitely divisible distributions based on joint work with T. Hasebe. Especially, some interesting distributional properties are founded comparing the classical probability. Oct. 20 15:00 - 16:30 RIMS 206 Narutaka Ozawa (RIMS) A functional analysis proof of Gromov's polynomial growth theorem The celebrated theorem of Gromov in 1980 asserts that any finitely generated group with polynomial growth contains a nilpotent subgroup of finite index. Alternative proofs have been given by Kleiner in 2007, Shalom--Tao in 2009, and Breuillard--Green--Tao in 2011. In this talk, I will give yet another proof of Gromov's theorem, along the lines of Shalom and Chifan--Sinclair, which is based on the analysis of reduced cohomology and Shalom's property $H_{\mathrm{FD}}$. Oct. 24-26 Myo-Ko Annual meeting on operator theory & operator algebra theory Nov. 09-11 RIMS 420 Research on structure of operators by order and geometry with related topics Nov. 10DT Seminar 15:00 - 16:30 Sci 6-609 Jeremie Brieussel (Montpellier) About the speed of random walk on solvable groups The speed of a random walk measures the average distance between the particle and its starting point. By Lee--Peres, for non-degenerate random walks on infinite groups, the speed is between $\sqrt{n}$ and $n$. By Amir--Virag, any regular function between $n^{3/4}$ and $n$ is the speed function of some random walk on some group. I will describe some solvable groups and some random walks on them with speed between $\sqrt{n}$ and $n^{3/4}$. Dec. 01 15:00 - 16:30 RIMS 206 Narutaka Ozawa (RIMS) Character Rigidity after Jesse Peterson Dec. 08DT Seminar 15:00 - 16:30 Sci 6-609 Narutaka Ozawa (RIMS) A functional analysis proof of Gromov's polynomial growth theorem Re-broadcasting. Dec. 12-13 Kinosaki Kansai Operator Algebra Seminar Jan. 12 15:00 - 16:30 RIMS 206 Gábor Szabó (Münster) Strongly self-absorbing C*-dynamical systems We discuss a generalization of the notion of strongly self-absorbing C*-algebras to the setting of C*-dynamical systems. The main result is an equivariant McDuff-type theorem that characterizes exactly when an action of a locally compact group on a separable C*-algebra absorbs a given strongly self-absorbing action tensorially up to cocycle conjugacy. This extends a similar folklore result that has been known for discrete group actions. I will present natural examples of strongly self-absorbing actions, and we then discuss what kind of (equivariant) permanence properties carry over in this context, similar to how D-stability is closed under various C*-algebraic operations. Jan. 25-27 RIMS 111 Some problems in operator algebras related to ergodic theory and group theory Feb. 23 15:00 - 16:30 RIMS 206 James Mingo (Queen's University, Kingston) Cumulants of Partially Transposed Random Matrices In quantum information theory the partial transpose of a positive matrix has been used to detect entanglement. I have recently investigated the effect of partial transposes on asymptotic freeness. The main tool for doing this is the use of free cumulants, both of first and second order. I will show how to use some simple geometric properties to find these cumulants.

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