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 Affiliation Rui OKAYASU Associate Professor Course for School Teacher Mathematics Education Osaka Kyoiku University Kashiwara, Osaka 582-8582 JAPAN Tel.: (+81) 72-978-3428 (my office) E-mail:
 Research Interest Operator Algebras
 Curriculum Vitae 2006.4--2003.4--2006.32003.32000.31998.3 Associate Professor, Osaka Kyoiku University Research Associate, Osaka Kyoiku University Ph.D., Mathematics, Kyoto University (Adviser: Prof. M. Izumi) M.Sc., Mathematics, University of Tokyo (Adviser: Prof. M. Izumi, Prof. Y. Kawahigashi) B.Sc., Mathematics, Tokyo University of Science
 Publications (List of publications from MathSciNet) [13] (With R. Tomatsu) Haagerup approximation property and positive cones associated with a von Neumann algebra. Preprint. arXiv:1403.3971 [12] (With M. Caspers, A. Skalski, R. Tomatsu) Generalisations of the Haagerup approximation property to arbitrary von Neumann algebras. C. R. Acad. Sci. Paris 352 (2014) 507--510. arXiv:1404.2716 [11] (With R. Tomatsu) Haagerup approximation property for arbitrary von Neumann algebras. Preprint. arXiv:1312.1033 [10] Free group $C^*$-algebras associated with $\ell_p$. Internat J. Math. 25 (2014), no.7, 1450065, 12 pp. arXiv:1203.0800 [9] Relative entropy for abelian subalgebras. Internat J. Math. 21 (2010), no.4, 537--550. [8] Entropy for $C^*$-algebras with tracial rank zero. Proc. Amer. Math. Soc. 138 (2010), no.10, 3609--3621. [7] (With M. Izumi and S. Neshveyev) The ratio set of the harmonic measure of a random walk on a hyperbolic group. Israel J. Math. 163 (2008), 285--316. [6] Perturbation theoretic entropy of the boundary actions of free groups. Proc. Amer. Math. Soc. 134 (2006), no.6, 1771--1776. [5] Gromov hyperbolic groups and the Macaev norm. Pac. J. Math. 223 (2006), no.1, 141--158. [4] $C^*$-algebras associated with the fundamental groups of graphs of groups. Math. Scand. 97 (2005), no.1, 49--72. [3] Entropy of subshifts and the Macaev norm. J. Math. Soc. Japan. 56 (2004), no.1, 177--191. [2] Type III factors arising from Cuntz-Krieger algebras. Proc. Amer. Math. Soc. 131 (2003), no.7, 2145--2153. [1] Cuntz-Krieger-Pimsner algebras associated with amalgamated free product groups. Publ. RIMS, Kyoto Univ. 38 (2002), no.1, 147--190.