関西作用素環セミナー

Kansai Operator Algebras Seminar


日時:2014年11月29日(土)〜30日(日)

場所:白浜町中央公民館(会議室)&民宿松風(宿)

アクセス:

(1) JR特急くろしお9号 新大阪11:00発→天王寺11:17発→白浜13:15着(→バス乗り換え)
(2) 高速バス
  1. 京都駅八条口8:00発→白浜桟橋11:52着(→徒歩)
  2. 大阪駅JR高速バスターミナル9:50発→JRなんば駅(OCAT)10:10発→白浜桟橋13:17着 (→徒歩)
(3) 南紀白浜空港 JAL 東京羽田10:30発→白浜南紀11:45着(→バス乗り換え)

参考ページ:

注意:宿にアメニティグッズ(タオル&浴衣)はありません

プログラム

29日(土)
明光バス12三段壁行き・白浜駅13:25発→常喜院下13:37着(310円)
14:00〜15:00
 
縄田紀夫
 
大阪教育大

 
Fundamental group of uniquely ergodic Cantor minimal systems
 
Abstract: We introduce the fundamental group $\mathcal{F}(\mathcal{R})$ of a uniquely ergodic Cantor minimal system $\mathcal{R}$. We show that if $\mathcal{R}$ arises from a free action of a finitely generated abelian group, then there exists a unital countable subring $R $ of $\mathbb{R}$ such that $\mathcal{F}(\mathcal{R})=R_{+}^\times$. Therefore $\{4^n\; |\; n\in\mathbb{Z}\}$ cannot be realized as the fundamental group of a uniquely ergodic Cantor minimal system in this class. We also consider the relation between fundamental groups of uniquely ergodic Cantor minimal $\mathbb{Z}^n$-systems and fundamental groups of crossed product $\mathrm{C}^*$-algebras $C(X)\rtimes \mathbb{Z}^n$.
15:15〜16:15
 
佐藤康彦
 
京大理
 
 
Classification of order zero c.p. maps by traces
 
Abstract: Order zero c.p. maps were systematically studied by W. Winter and J. Zacharias, based on the previous work by M. Wolf. These are c.p. maps preserving orthogonality, they are particularly well-behaved. In this talk, we introduce a classification of certain order zero c.p. maps up to approximate unitary equivalence by their behavior on tracial states. As an application of this classification, it was shown that the nuclear dimension of unital separable simple amenable $\mathcal{Z}$-absorbing $\mathrm{C}^*$-algebra is at most one if its extreme boundary of trace space is compact. This is a joint work with J. Bosa, N. P. Brown, A. Tikuisis, S. White, and W. Winter.
明光バス12三段壁行き・常喜院下16:30発→南千畳16:39着(280円)
18:00〜21:00 懇親会



30日(日)
明光バス11田辺駅行き・南千畳9:06発→常喜院下9:15着(280円)
9:30〜10:30  
 
荒野悠輝
 
東大数理
 
 
Unitary spherical representations of Drinfeld doubles
 
Abstract: The Drinfeld double of a q-deformation of a connected simply connected compact Lie group can be considered as a quantum analogue of the complexification of the Lie group. In this talk, we focus on irreducible spherical unitary representations of such Drinfeld doubles. In the case of $\mathrm{SU}_q(3)$, we give a complete classification of such representations. We also show the Drinfeld double of the quantum group $\mathrm{SU}_q(2n+1)$ has property (T), which also implies central property (T) of the dual of $\mathrm{SU}_q(2n+1)$.
10:45〜11:45
 
鈴木悠平
 
東大数理/RIMS
 
 
Group $\mathrm{C}^*$-algebras as decreasing intersection of nuclear $\mathrm{C}^*$- algebras
 
Abstract: We will see that for any discrete group with the AP, the reduced group $\mathrm{C}^*$-algebra is realized as a decreasing intersection of nuclear $\mathrm{C}^*$-algebras. This in particular says that unlike the $\mathrm{W}^*$-case, the decreasing intersection of nuclear $\mathrm{C}^*$-algebras can behave badly. In fact, it turned out that the decreasing intersection of nuclear $\mathrm{C}^*$-algebras does not need to have the OAP and the LLP, even when the decreasing sequence admits a compatible family of conditional expectations.
明光バス11田辺駅行き・常喜院下12:03発→白浜駅12:15着(310円)

参加者名簿(2014/11/26現在)

  1. 河東泰之
  2. 木田良才
  3. 縄田紀夫
  4. 長田まりゑ
  5. 佐藤康彦
  6. Benoit Collins
  7. 鈴木悠平
  8. 見村万佐人
  9. 嶌田洸一
  10. 河上哲
  11. 釣井達也
  12. 片山良一
  13. 泉正己
  14. 荒野悠輝
  15. 山中聡恵
  16. 小澤登高
  17. 戸松玲治
  18. 岡安類


日時:2014年6月28日(土)

場所:奈良教育大学 新館2号棟(R-5)2階 211講義室

プログラム

14:00〜15:00
 
Cyril Houdayer
 
ENS Lyon

 
Asymptotic structure of free Araki-Woods factors
 
Abstract : I will report on some new structural results for free Araki-Woods factors and their modular invariant subalgebras. This is joint work with Sven Raum.
15:15〜16:15
 
嶌田洸一
 
東大数理
 
 
On actions of compact abelian groups on subfactors.
 
Abstract : Classification of actions of discrete abelian groups on subfactors are studied by many researchers, including Loi, Popa, Kawahigashi, Winsløw and Masuda. Here, we generalize their results for certain inclusions of von Neumann algebras which may not be factors. As an application, we obtain some results about actions of compact abelian groups on certain subfactors.