Apr. 11 
15:00  16:30 RIMS 206 
Yuki Arano (Kyoto)
Cohomology of quantum groups
Cohomology of a tensor category has been recently introduced by PopaShlyakhtenkoVaes and computed in the quantum sl_2 case by KyedRaumVaesValvekens using the DrinfeldYetter resolution obtained by Bichon. In this talk, we compute this cohomology for the higher rank case.


Apr. 14May 26 TGU Lecture 
Sci 3127 
Nigel Higson (Penn State/Kyoto)
The Noncommutative Geometry of Tempered Representations
April 14(F) 10:00  12:00, 21(F) 10:00  12:00, 28(F) 10:00  12:00 / 14:0016:00, May 12(F) 10:00  12:00 / 14:00  16:00, 19(F) 10:00  12:00, 26(F) 10:00  12:00.


Apr. 18 
15:00  16:30 RIMS 206 
Yasuyuki Kawahigashi (Tokyo)
The relative Drinfeld commutant and alphainduction
We study relative Drinfeld commutants of a fusion category in another fusion category in terms of halfbraidings. We identify halfbraidings with minimal central projections of the relative tube algebra and certain sectors of the LongoRehren subfactors. We apply this general machinery to various fusion categories arising from alphainduction and compute the relative Drinfeld commutants explicitly.


Apr. 20 Séminaire de travail 
10:00  RIMS 106 
Koichi Shimada (Kyoto)
KadisonSinger Problem (MarcusSpielmanSrivastava Theorem) 1


Apr. 25 
15:00  16:30 RIMS 206 
Narutaka Ozawa (RIMS)
Introduction to Tsirelson's Problem
Tsirelson's problem (in the weaker form) is one of the most important problem in quantum information theory, which is known to be equivalent to Connes's embedding problem. I will review it from an algorithmic point of view. The lecture also cover Slofstra's recent negative solution to the original (i.e., stronger) Tsirelson problem.


Apr. 26 (Wed) Colloquim 
16:30  17:30 Sci 3110 
Yusuke Isono (RIMS)
フォンノイマン環とdeformation/rigidity理論の紹介


Apr. 27 Séminaire de travail 
10:00  RIMS 106 
Koichi Shimada (Kyoto)
KadisonSinger Problem (MarcusSpielmanSrivastava Theorem) 2


May 09 
15:00  16:30 RIMS 206 
Nigel Higson (PennState/Kyoto)
C*algebras and the uniform admissibility of the discrete series
Many aspects of HarishChandra’s theory of tempered representations fit very naturally with C*algebra theory and noncommutative geometry. The principal results are easy to express in the language of C*algebras, and moreover there are noncommutativegeometric arguments that explain quite conceptually the general form of tempered representation theory, as I shall try to demonstrate. An exception, at least for the time being, is the “uniform admissibility property” of the discrete series. I shall explain what this property is, why it is important, and how it might be approached through C*algebras and noncommutative geometry.


May 1113 Workshop 
Sci 3127 
Advances in non commutative geometry


May 16 
15:00  16:30 RIMS 206 
Yasuhiko Sato (Kyoto)
Actions of amenable groups and absorption of the JiangSu algebra
In the recent classification theory of $\mathrm{C}^*$algebras, the absorption of the JiangSu algebra $\mathcal{Z}$ plays a central role. Actually, A. S. Toms and W. Winter conjectured that $\mathcal{Z}$absorption is equivalent to other regularity properties, such as strict comparison and finiteness of nuclear dimension, for standard nuclear $\mathrm{C}^*$algebras. Now, we know that this conjecture holds true under the assumption of unique tracial state.
In this talk, we study a permanence property of $\mathcal{Z}$absorption for crossed products by countable amenable groups. Assuming strict comparison and uniqueness of tracial state, we show that the crossed product of unital separable simple nuclear $\mathrm{C}^*$algebra absorbs the JiangSu algebra again.


May 23 
15:00  16:30 RIMS 206 
Norio Nawata (Osaka Kyoiku)
Trace scaling automorphisms of $\mathcal{W}\otimes\mathbb{K}$
We classify trace scaling automorphisms of $\mathcal{W}\otimes\mathbb{K}$ up to outer conjugacy, where $\mathcal{W}$ is a certain simple separable nuclear stably projectionless C$^*$algebra having trivial $K$groups. Mainly, we talk about a homotopy type theorem of unitaries in the central sequence C$^*$algebra $F(\mathcal{W})$ of $\mathcal{W}$.


May 25 
10:45  11:45 Sci 3108 
Tulio Gaxiola (CIMAT&Tohoku)
Spectral Analysis of Graphs: a NonCommutative Probabilistic outlook
In this talk we introduce some results about the relation of spectral distributions of some products of graphs with notions of noncommutative independece. Moreover, we explain recent results, in collaboration with Octavio Arizmendi, on spectral distribution of distancek graphs of star and free products of graphs.


May 25 
13:15  14:15 Sci 3108 
Camille Male (Bordeaux & CNRS)
Non commutative notions of independences
The convergence in traffic distribution of matrices enriches the convergence in non commutative distribution, and makes tractable the description of the limiting distribution of matrices invariant in law by permutation of the elements of the basis (in particular, of random graphs). In this presentation I will present three particular situations where the traffic independence reduces respectively to the free, the tensor or the Boolean independence.


May 2902 Intensive Lecture Course 
Sci 3127 
Yoshimichi Ueda (Kyushu)
ランダム行列に対する大偏差原理
29(M) 15:00  17:00, 30(T) 15:00  17:00, 31(W) 10:00  12:00, 01(T) 15:00  17:00, 02(F) 10:00  12:00. Colloquium May 31(W), 16:30  17:30
ランダム行列の固有値経験分布に対する大偏差原理を解説する．また，ランダム行列（の固有値経験分布）の行列サイズ無限大極限を記述する自然な枠組みとしての自由確率論を紹介する．なお，学部で習う標準的な測度論の知識は仮定するが，確率論の特別な知識は仮定しない．


May 31 (Wed) Colloquim 
16:30  17:30 Sci 3110 
Yoshimichi Ueda (Kyushu)
ランダム行列と作用素環


June 01 Séminaire de travail 
10:00  RIMS 106 
Koichi Shimada (Kyoto)
KadisonSinger Problem (MarcusSpielmanSrivastava Theorem) 3


June 15 Séminaire de travail 
10:00  RIMS 106 
Koichi Shimada (Kyoto)
KadisonSinger Problem (MarcusSpielmanSrivastava Theorem) 4


June 20 
15:00  16:30 RIMS 206 
Reiji Tomatsu (Hokkaido)
Ultraproducts of crossed product von Neumann algebras
I will explain how to treat an ultraproduct von Neumann algebra of a crossed product von Neumann algebra using the notion of equicontinuity.


June 2628 Workshop 
RIMS 110 
Mathematical Aspects of Quantum Fields and Related Topics


July 05 (Wed) Colloquim 
16:30  17:30 RIMS 110 
Yuki Arano (Kyoto)
部分因子環論と表現論


July 11 
15:00  16:30 RIMS 206 
Sakie Suzuki (RIMS)
The universal quantum invariant and colored ideal triangulations
The Drinfeld double of a finite dimensional Hopf algebra is a quasitriangular Hopf algebra with the canonical element as the universal Rmatrix, and one can obtain a ribbon Hopf algebra by adding the ribbon element. The universal quantum invariant of framed links is constructed using a ribbon Hopf algebra. In that construction, a copy of the universal Rmatrix is attached to each crossing, and invariance under the Reidemeister III move is shown by the quantum YangBaxter equation of the universal Rmatrix.
On the other hand, the Heisenberg double of a finite dimensional Hopf algebra has the canonical element (the Stensor) satisfying the pentagon relation. In this talk we reconstruct the universal quantum invariant using the Heisenberg double, and extend it to an invariant of equivalence classes of colored ideal triangulations of 3manifolds up to colored moves. In this construction, a copy of the Stensor is attached to each tetrahedron, and invariance under the colored Pachner (2,3) moves is shown by the pentagon relation of the Stensor.
任意の有限次元ホップ代数のDrinfeld doubleはcanonical elementを普遍R行列にもつquasitriangularホップ代数になり．さらにリボン元を付け加えることでリボンホップ代数が得られる．普遍量子不変量とはリボンホップ代数と絡み目図式を用いて構成される枠付き絡み目の不変量である．その構成の中では図式の正交点に普遍R行列が対応し，普遍R行列の量子YangBaxter方程式がライデマイスターIII移動の下での不変性を保証する．一方，任意の有限次元ホップ代数のHeisenberg doubleのcanonical element（Sテンソル）は5角関係式を満たす．この講演ではHeisenberg doubleを用いて普遍量子不変量を絡み目補空間の色付き理想単体分割の不変量として再構成し，さらにそれを絡み目補空間の色付き理想単体分割の不変量として拡張する．この構成では理想単体にSテンソルが対応し，色付き理想単体分割のPachner (2,3) moveの下での不変性をSテンソルの５角関係式が保証する．


July 13 Séminaire de travail 
10:00  RIMS 106 
Narutaka Ozawa (RIMS)
Strong property (T) after Lafforgue


July 18 Hakubi Seminar 
16:30  Hakubi Center 
Yusuke Isono (RIMS)
フォンノイマン環論の紹介
フォンノイマン環論とは，フォンノイマンが量子力学を研究するために作った数学理論である． 非常に雑に言えば，大学一年生で学ぶ線形代数を「無限に大きなサイズの行列」に対して考えるものである． 当初は物理学への応用を念頭において研究されていたが，現在では純粋な数学理論としても研究されている． 実際，K理論，結び目，エルゴード理論，表現論など多くの数学理論と密接に関係しており，非常に興味深い数学理論である． 一方で，無限次元である事が原因で，その取扱いは極めて難解である． いわゆる代数，幾何，解析のそれぞれの知識を活用した研究が必要とされる．この講演では，数学理論としてのフォンノイマン環論の紹介を行う．特に予備知識は仮定せず， どのように定義されるのか，どのような点が難しいのか，どのような問題を考えているのか， 等の基本的な事を理解してもらう事を目標とする．


July 20 Séminaire de travail 
10:00  RIMS 106 
Yuki Arano (Kyoto)
Classification of subfactors of finite depth (after Popa)


July 25 Séminaire de travail 
15:00  RIMS 206 
Hiroshi Ando (Chiba)
Noncommutative Grothendieck inequality and amenability of nuclear C* algebras (after Haagerup)


July 26 Wed 
Sci 3127 
Workshop on interactions between commutative and noncommutative probability


Sep. 0406 
RIMS 111 
Recent developments in operator algebras
(program)


Oct. 05 DT seminar 
15:00  16:30 Sci 6609 
Raphael Ponge (Seoul)
Cyclic homology and group actions on manifolds


Oct. 11 Colloquim 
16:30  17:30 RIMS 110 
Mikael Pichot (McGill/RIMS)
Nonpositive curvature and operator algebras
The field of operator algebras was begun in the late 1920's by J. von Neumann, through his work on abstract Hilbert spaces and the foundation of quantum mechanics. The subject developed steadily for nearly a century, and found deep connections with many branches of mathematics. The talk will discuss, using concrete examples, some of these connections, in particular with group theory and geometry of nonpositive curvature. The main focus will be the recent work of Sylvain Barré and myself on intermediate rank geometry.
I will give some motivation for this work, and explain some of the leading ideas in the study of discrete groups of intermediate rank.


Oct. 17 
15:00  16:30 RIMS 206 
Masaki Izumi (Kyoto)
Group Actions on Kirchberg Algebras


Oct. 31 DT Seminar 
15:00  16:30 Sci 6609 
François Dahmani (Grenoble)
Conjugacy of automorphisms: on the conjugacy problem for certain automorphisms of free groups


Nov. 01 Séminaire de travail 
13:30  RIMS 109 
Yuki Arano (Kyoto)
Maharam


Nov. 07 DT Seminar 
15:00  16:30 Sci 6609 
Tomohiro Fukaya (TMU)
Coarse CartanHadamard theorem and an application to the coarse BaumConnes conjecture


Nov. 14 
15:00  16:30 RIMS 206 
Yoshikata Kida (Tokyo)
Central sequences in the full group and compact extensions
We discuss when an orbit equivalence relation admis a nontrivial central sequence in its full group. Among others, we show that existence of such a sequence is stable under compact extension of equivalence relations. Related results and examples are also discussed.


Nov. 15 Séminaire de travail 
13:30  RIMS 109 
Takuya Takeishi (RIMS)
Semigroup actions and Ktheory (after arxiv:1205.5412)


Nov. 1719 
Ritsumei BKC 
Annual Meeting on operator theory & operator algebra theory


Nov. 21 
15:00  16:30 RIMS 206 
Kei Hasegawa (Kyushu)
Boundary rigidity for free product C*algebras
For a reduced free product of C*algebras, we prove a boundary rigidity result for the embedding of it into the associated ``crossed product'' C*algebra under the assumption that the GNS representations associated with the distinguished states are essential and one of free components satisfies a suitable diffuseness condition. This provides new examples of rigid embeddings of exact C*algebras into purely infinite simple nuclear C*algebras.


Nov. 22 Séminaire de travail 
13:30  RIMS 109 
Yusuke Isono (RIMS)
Locally compact group actions and Cartan rigidity (after arxiv:1703.09092)


Nov. 28 
15:00  16:30 RIMS 206 
Narutaka Ozawa (RIMS)
Kazhdan's property (T) and semidefinite programming
Kazhdan's property (T) for groups has a number of applications in
pure and applied mathematics. It has long been thought that
groups with property (T) are rare among the "naturallyoccurring"
groups, but it may not be so and it may be possible to observe
this by extensive computer calculations. After an introduction,
I will present a computer assisted (but mathematically rigorous)
method of confirming property (T) based on semidefinite
programming with some operator algebraic input. I will report the
progress recently made in collaboration with M. Kaluba, P. Nowak,
and PLgrid, a Polish supercomputer. It confirms property (T) of
Aut(F_5), which solves a wellknown problem in geometric group
theory, at least partially, leaving the tantalizing question in
the case of Aut(F_d), d=4 and d>5, unsettled.


Dec. 01 DS Seminar 
14:00  17:00 Sci 6609 
Masaki Tsukamoto (Kyoto)
Expansive multiparameter actions and mean dimension


Dec. 05 
15:00  16:30 RIMS 206 
Mikael Pichot (McGill/RIMS)
On Aut(F_2)
I will explain things related to the automorphism group of $F_2$ from a geometric perspective.


Dec. 09 
OKU Tennōji 
Kansai Seminar


Dec. 11 VOA workshop 
10:00  10:50 RIMS 420 
Yasuyuki Kawahigashi (Tokyo)
Representation theories of vertex operator algebras and operator algebras


Dec. 19 
15:00  16:30 RIMS 206 
Makoto Yamashita (Ochanomizu)
Tube representations of graded categories
We study the structure of tube algebra under graded twist of tensor categories. This deformation scheme played a central role in the KazhdanWenzl classification of semisimple tensor categories with the fusion rules of $\mathrm{SL}_n$, and at the simplest case it relates quantum $\mathrm{SU}(2)$ group at the parameter $q$ and $q$. Motivated by the 2cocycle deformation result for tube algebras of pointed categories due to Bisch, Das, Ghosh, Rakshit, we give a general formula describing annular algebra of 3cocycle deformation categories as 2cocycle deformation of Fell bundle over a groupoid. Based on joint work with Bhowmick, Ghosh, Rakshit.


Dec. 20 Séminaire de travail 
13:30  RIMS 109 
Yuki Arano (Kyoto)
Subfactor


Jan. 09 
15:00  16:30 RIMS 206 
Jean Roydor (Bordeaux/Jussieu)
BanachMazur stability of von Neumann algebras
We study perturbation of von Neumann algebras relatively to the BanachMazur distance. We prove that, under some cohomological conditions, two von Neumann algebras which are close are necessarily Jordan isomorphic (thus isometric).


Jan. 23 
15:00  16:30 RIMS 206 
Ulrich Pennig (Cardiff)
A DixmierDouady theory for strongly selfabsorbing C*algebras
I will report on joint work with Marius Dadarlat. We showed that the DixmierDouady theory of continuous fields of C*algebras with compact operators as fibres extends to a more general theory of fields with fibres stabilised strongly selfabsorbing C*algebras. The classification of the corresponding locally trivial fields involves a generalised cohomology theory obtained from the unit spectrum of topological KTheory, which is computable via the AtiyahHirzebruch spectral sequence. An important feature is the appearance of characteristic classes in higher dimensions. We found a necessary and sufficient Ktheoretical condition for local triviality of these continuous fields over spaces of finite covering dimension.


Jan. 2426 
RIMS 420 
Mathematical study on topological phases
(program)


Feb. 07 Wednesday 
13:00  14:30 Sci 3109 
HaoWei Huang (Sun Yatsen Univ)
Bifreely infinite divisibility of unitary faces
In free probability theory the notion of free multiplicative convolution of probability distributions on the unit circle has played an important role since its inception by Voiculescu some $30$ years ago. In 2013, Voiculescu generalized the notion of free independence to study left and right actions on reduced free product spaces simultaneously, known as bifree independence. One generalization of the free multiplicative convolution to the bifree setting is the bifree multiplicative convolution of probability distributions on the unit bitorus. In this talk, we will introduce an analytic machinery to study Voiculescu's bifree partial $S$transform and use it to characterize the multiplicative bifree infinite
divisibility on the unit bitorus. This is joint work with J.C. Wang.


Feb. 16 Friday 
14:30  16:00 Sci 3109 
Sven Raum (EPFL)
Cartan subalgebras in dimension drop algebras
I will report about recent work on Cartan subalgebras of stabilised dimension drop algebras. Starting with an introduction to the topic, which includes motivation, I will proceed to explain a complete classification up to conjugacy by an automorphism of Cartan subalgebras in dimension drop algebras with coprime parameters. Moreover, in this setting two Cartan subalgebras are conjugate if and only if their spectrum is homeomorphic, providing the tamest possible classification result for C*algebraic Cartan subalgebras.
This is joint work with S. Barlak.


16:15  17:45 Sci 3109 
Xin Li (QMUL)
Constructing Cartan subalgebras in classifiable C*algebras
After brief introductions to Elliott's classification programme and Cartan subalgebras in C*algebras, I will explain how to construct Cartan subalgebras in large classes of classifiable C*algebras.


Feb. 20 
14:30  16:00 RIMS 206 
Michiya Mori (Tokyo)
Tingley's problem for operator algebras
Tingley's problem asks whether every surjective isometry between the unit spheres of two Banach spaces admits an extension to a real linear surjective isometry between the whole spaces. Tingley's problem between real Banach spaces has been considered for more than 30 years. In recent years, using the facial structure of unit balls, some researchers solved Tingley's problem between operator algebras affirmatively in several settings. In this talk, I explain the history of this problem and my new results concerning Tingley's problem for operator algebras.


16:15  17:45 RIMS 206 
Alessandro Carderi (Dresden)
Asymptotic invariants of lattices in locally compact groups
The aim of our work is to understand some of the asymptotic properties of sequences of lattices in a fixed locally compact group. As an example we are interested in the asymptotic growth of the Betti numbers of the lattices renormalized by the covolume or the rankgradient, the minimal number of generator also renormalized by the covolume. For doing so we will consider the ultraproduct of the actions of the locally compact group on the coset spaces and we will show how the properties of one of its cross sections are related to the asymptotic properties of the lattices.

