OZAWA Narutaka

J-GLOBAL         Last updated: Sep 19, 2019 at 15:45
OZAWA Narutaka
Kyoto University
Research Institute for Mathematical Sciences
(BLANK)(The University of Tokyo), Ph. D. (Mathematics)(Texas A&M University)

Research Interests


Research Areas


Academic & Professional Experience

Apr 2013
Professor, Research Institute for Mathematical Sciences, Kyoto University
Apr 2011
Mar 2013
Associate Professor, Research Institute for Mathematical Sciences, Kyoto University
Apr 2004
Mar 2011
Associate Professor, Graduate School of Mathematical Sciences, The University of Tokyo 
Apr 2000
Mar 2004
Assistant Professor, Graduate School of Mathematical Sciences, The University of Tokyo 


Graduate School, Division of Mathematical Sciences, The University of Tokyo

Awards & Honors

Study of discrete groups and operator algebras, Spring Prize, Mathematical Society of Japan
Winner: Narutaka OZAWA
Theory of Discrete Groups and Operator Algebras, JSPS Prize, Japan Society for the Promotion of Science
Winner: Narutaka OZAWA

Published Papers

M. Anoussis, N. Ozawa, I. G. Todorov
Proc. Amer. Math. Soc.   147 2057-2068   2019   [Refereed]
Breuillard Emmanuel, Kalantar Mehrdad, Kennedy Matthew, Ozawa Narutaka
PUBLICATIONS MATHEMATIQUES DE L IHES   126(126) 35-71   Nov 2017   [Refereed]
De Chiffre Marcus, Ozawa Narutaka, Thom Andreas
MATHEMATIKA   65(1) 98-118   2019   [Refereed]
Ozawa Narutaka
Erschler Anna, Ozawa Narutaka
COMMENTARII MATHEMATICI HELVETICI   93(3) 555-586   2018   [Refereed]
Okayasu Rui, Ozawa Narutaka, Tomatsu Reiji
MATHEMATICA SCANDINAVICA   121(1) 75-91   2017   [Refereed]
Ozawa Narutaka
COMPOSITIO MATHEMATICA   152(12) 2493-2502   Dec 2016   [Refereed]
Narutaka Ozawa, Mikael Rørdam, Yasuhiko Sato
Geometric and Functional Analysis   25 307-316   2015   [Refereed]
© 2015, Springer Basel. We show that the group C*-algebra of any elementary amenable group is quasidiagonal. This is an offspring of recent progress in the classification theory of nuclear C*-algebras.
David P. Blecher, Narutaka Ozawa
Pacific Journal of Mathematics   277 1-59   2015   [Refereed]
© 2015 Mathematical Sciences Publishers. Blecher and Read recently introduced and studied a new notion of positivity in operator algebras, with an eye to extending certain C*-algebraic results and theories to more general algebras. In the present ...
Narutaka Ozawa
Proceedings of the Japan Academy Series A: Mathematical Sciences   91 104-104   2015   [Refereed]
© 2015 The Japan Academy. We give a simple proof of a theorem of C. Houdayer that an amenable von Neumann subalgebra in a tracial free product von Neumann algebra M = M<inf>1</inf> * M<inf>2</inf> is contained in M<inf>1</inf> whenever it has a di...
Masato Mimura, Narutaka Ozawa, Hiroki Sako, Yuhei Suzuki
Algebraic and Geometric Topology   15 1061-1091   2015   [Refereed]
© 2015, Algebraic & Geometric Topology. All Rights Reserved. In this series of papers, we study the correspondence between the following: (1) the large scale structure of the metric space ⊔m Cay (G (m) consisting of Cayley graphs of finite groups ...
G. Godefroy; N. Ozawa
Proceedings of the American Mathematical Society   142(5) 1681-1687   2014   [Refereed]
We characterize the metric spaces whose free spaces have the bounded approximation property through a Lipschitz analogue of the local reflexivity principle. We show that there exist compact metric spaces whose free spaces fail the approximation pr...
Yemon CHOI, Ilias FARAHA, Narutaka OZAWA
Forum Math. Sigma   2(e2)    2014   [Refereed]
M. Burger; N. Ozawa; A. Thom
Israel Journal of Mathematics   193(1) 109-129   Jan 2013   [Refereed]
Dixmier approximation and symmetric amenability for c*- algebras
N. Ozawa
Journal of Mathematical Sciences, the University of Tokyo   20(3) 349-374   2013   [Refereed]
N. Ozawa
Kyushu Journal of Mathematics   67(1) 51-53   Mar 2013   [Refereed]
N. Ozawa
Journal of Mathematical Physics   54(3)    2013   [Refereed]
N. Ozawa
Japanese Journal of Mathematics   8(1) 147-183   2013   [Refereed]
W.B. Johnson; N. Ozawa; G. Schechtman
Proceedings of the National Academy of Sciences of the United States of America   110(48) 19251-19255   2013   [Refereed]
Let A be an m × m complex matrix with zero trace and let ε > 0. Then there are m × m matrices B and C such that A = [B,C] and ||B||||C|| ≤ Kεmε||A|| where K ε depends only on ε. Moreover, the matrix B can be taken to be normal.
N. Ozawa
Kyoto Journal of Mathematics   52(2) 333-344   2012   [Refereed]
N. Monod; N. Ozawa; A. Thom
International Journal of Algebra and Computation   22(4)    Jun 2012   [Refereed]
N. Ozawa
International Journal of Algebra and Computation   22(2)    2012   [Refereed]
Ozawa, Narutaka; Popa, Sorin
ANNALS OF MATHEMATICS   172(1) 713-749   Jul 2010   [Refereed]
Weak amenability for groups III
Narutaka Ozawa
「作用素環ウィンター・スクール」 (Winter School on Operator Algebras), 2011 年12 月9 日( 金)      2011   [Refereed]
N. Ozawa
Journal fur die Reine und Angewandte Mathematik   (655) 89-104   2011   [Refereed]
N. Ozawa; S. Popa
American Journal of Mathematics   132(3) 841-866   Jun 2010   [Refereed]
N. Monod; N. Ozawa
Journal of Functional Analysis   258(1) 255-259   2010   [Refereed]
Ozawa Narutaka
HOKKAIDO MATHEMATICAL JOURNAL   38(3) 557-561   Aug 2009   [Refereed]
Weak amenability of hyperbolic groups
Ozawa, Narutaka
GROUPS GEOMETRY AND DYNAMICS   2(2) 271-280   2008   [Refereed]
C*-algebras and finite-dimensional approximations
N. P. Brown , N. Ozawa
Graduate Studies in Mathematics, 88. American Mathematical Society, 2008, 509 pp      2008   [Refereed]
N. Ozawa
Journal of the Mathematical Society of Japan   59(4) 985-991   Oct 2007   [Refereed]
Amenable actions and applications
N. Ozawa
International Congress of Mathematicians, ICM 2006   2 1563-1580   2006   [Refereed]
Ozawa Narutaka
N. Ozawa
International Mathematics Research Notices   2006 1-21   2006   [Refereed]
N. Ozawa
Topology and its Applications   153(14) 2624-2630   Aug 2006   [Refereed]
N. Ozawa; M.A. Rieffel
Canadian Journal of Mathematics   57(5) 1056-1079   2005   [Refereed]
Narutaka Ozawa
Bull. Lond. Math. Soc. 39 (2007), 35--38   39(1) 35-38   Nov 2004   [Refereed]
We prove that the crossed product Tex-algebra
Tex of a free group Tex with its boundary
Tex naturally sits between the reduced group Tex-algebra
Tex and its injective envelope $I(C^*_r\Gam...
Narutaka Ozawa
   Nov 2004
The theory of exact C*-algebras was introduced by Kirchberg and has been
influential in recent development of C*-algebras. A fundamental result on exact
C*-algebras is a local characterization of exactness. The notion of weakly
exact von Neumann a...
N. Ozawa
Proceedings of the American Mathematical Society   132(2) 487-490   Feb 2004
Gromov constructed uncountably many pairwise nonisomorphic discrete groups with Kazhdan's property (T). We will show that no separable II 1-factor can contain all these groups in its unitary group. In particular, no separable II1-factor can contai...
Narutaka Ozawa
   Jan 2004
This is an expository note on non-amenabilty of the Banach algebra B(\ell_p)
for p=1,2. These were proved respectively by Connes (p=2) and Read (p=1) via
very different methods. We give a single proof which reproves both.
Narutaka Ozawa
Int. Math. Res. Not., Volume 2006, Article ID97560      Jan 2004
We prove a Kurosh type theorem for free-product type II_1 factors. In
particular, if M = LF_2 \otimes R, then the free-product type II_1 factors
M*...*M are all prime and pairwise non-isomorphic. This paper is a continuation
of [N. Ozawa, Solid vo...
N. Ozawa
International Journal of Mathematics   15(6) 557-565   2004   [Refereed]
N. Ozawa
International Journal of Mathematics   15(5) 501-530   2004   [Refereed]
N. Ozawa; S. Popa
Inventiones Mathematicae   156(2) 223-234   2004   [Refereed]
N. Ozawa
Acta Mathematica   192(1) 111-117   2004   [Refereed]
Narutaka Ozawa
   Jun 2003
This is a detailed survey on the QWEP conjecture and Connes' embedding
problem. Most of contents are taken from Kirchberg's paper [Invent. Math. 112
Narutaka Ozawa
   Feb 2003
We prove that the relative commutant of a diffuse von Neumann subalgebra in a
hyperbolic group von Neumann algebra is always injective. It follows that any
non-injective subfactor in a hyperbolic group von Neumann algebra is non-Gamma
and prime. T...
Homotopy invariance of AF-embeddability
N. Ozawa
Geometric and Functional Analysis   13(1) 216-222   2003   [Refereed]
A. Kishimoto; N. Ozawa; S. Sakai
Canadian Mathematical Bulletin   46(3) 365-372   2003   [Refereed]
M. Junge; N. Ozawa; Z.-J. Ruan
Mathematische Annalen   325(3) 449-483   2003   [Refereed]


Survey on weak amenability
Narutaka Ozawa
国際研究集会「C ゛環および関連する話題」(Conference on C*-Algebras and Related Topics)、2011 年9 月8 日( 木)      2011   [Refereed]
Survey on weak amenability for groups
Narutaka Ozawa
Conference on von Neumann Algebras and Related Topics      2012   [Refereed]

Books etc

Nathanial P. Brown and Narutaka Ozawa
American Mathematical Society   Mar 2008   ISBN:0821843818

Conference Activities & Talks

Full factors and co-amenable inclusions [Invited]
OZAWA Narutaka
C*-Algebras   Aug 2019   
Kazhdan's property (T) and semidefinite programming [Invited]
OZAWA Narutaka
Conference: SYM 10 Years Old   Jun 2019   
Finite-dimensional representations constructed from random walks [Invited]
OZAWA Narutaka
2018 Spring Probability Workshop   Jun 2018   
Aut(F_5) has Kazhdan's property (T) [Invited]
OZAWA Narutaka
Approximation Properties in Operator Algebras and Ergodic Theory   Apr 2018   
Minicourse on Connes's Embedding Problem and its equivalent [Invited]
OZAWA Narutaka
Analysis in Quantum Information Theory   Sep 2017   

Research Grants & Projects

Noncommutative Analysis and Functional Analytic Group Theory
Japan Society for the Promotion of Science: KAKEN
Project Year: Apr 2014 - Mar 2017    Investigator(s): Narutaka OZAWA
Operator Space Theory and Its Application to Operator Algebra Theory