TAKEI Yoshitsugu
Faculty of Science and Engineering Department of Mathematical Sciences
Professor
Last Updated :2020/12/03

Researcher Profile and Settings

Research Interests

  • Differential Equations

Research Areas

  • Natural sciences/Basic analysis

Academic & Professional Experience

  • Faculty of Science and Engineering, Department of Mathematical Science, Doshisha University, 2017 - Today
  • Research Institute for Mathematical Sciences, Kyoto University, 2007 - 2017
  • Research Institute for Mathematical Sciences, Kyoto University, 1993 - 2007
  • Faculty of Science, Kyoto University, 1990 - 1993
  • Instructor, Faculty of Science, Kyoto University, 1990 - 1993
  • - Associate Professor, Research Institute for, 1993
  • Mathematical Sciences, Kyoto University

Education

  • Kyoto University, Graduate School, Division of Natural Science, 1990
  • Kyoto University, Faculty of Science, 1980 - 1984
  • Kyoto University, Faculty of Science, 1984

Academic Degrees

  • Doctor of Science, Kyoto University
  • Master of Science, Kyoto University

Association Memberships

  • Mathematical Society of Japan

Published Papers

  • Pearcey system re-examined from the viewpoint of s-virtual turning points and non-hereditary turning points
    Sampei Hirose, Takahiro Kawai, Yoshitsugu Takei
    RIMS Kokyuroku Bessatsu (preprint RIMS-1878), 75151 - 175, Jun. 2019, English
  • Extension of the exact steepest descent method to the middle convolution
    Yoshitsugu Takei
    2101146 - 152, 2019, English, Research paper (international conference proceedings)
  • On the instanton-type expansions for Painlevé transcendents and elliptic functions
    Yoshitsugu Takei
    365 - 377, 2019, English, Research paper (international conference proceedings)
  • On Stokes phenomena for the alternate discrete PI equation
    N. Joshi, Y. Takei
    Analytic, Algebraic and Geometric Aspects of Differential Equations, 369 - 381, 2017
  • WKB analysis and Stokes geometry of differential equations
    Yoshitsugu Takei
    Analytic, Algebraic and Geometric Aspects of Differential Equations, 263 - 304, 2017, English, Research paper (international conference proceedings)
  • Toward the exact WKB analysis of discrete Painleve equations
    N. Joshi, Y. Takei
    RIMS Kokyuroku Bessatsu, B6183 - 6, 2017, English, Research paper (international conference proceedings)
  • On the fourth order PI equation and coalescing phenomena of nonlinear turning points
    Yoshitsugu Takei
    RIMS Kokyuroku Bessatsu, B52301 - 316, 2014, English, Research paper (international conference proceedings)
  • Exact WKB analysis of second-order non-homogeneous linear ordinary differential equations
    T. Koike, Y. Takei
    RIMS Kokyuroku Bessatsu, B40293 - 312, 2013, English, Research paper (international conference proceedings)
  • On the role of the degenerate third Painleve equation of type (D8) in the exact WKB analysis
    Yoshitsugu Takei
    RIMS Kokyuroku Bessatsu, B37211 - 222, 2013, English, Research paper (international conference proceedings)
  • Probleme de Cauchy et Goursat analytique
    Y. Hamada, T. Okaji, Y. Takei
    Publications of the Research Institute for Mathematical Sciences, 48(1)139 - 181, 2012, Francese, Research paper (scientific journal)
  • On the turning point problem for instanton-type solutions of Painleve equations
    Yoshitsugu Takei
    Asymptotics in Dynamics, Geometry and PDEs; Generalized Borel Summation, 2255 - 274, 2011, English, Research paper (international conference proceedings)
  • On a Schrodinger equation with a merging pair of a simple pole and a simple turning point
    S. Kamimoto, T. Kawai, T. Koike, Y. Takei
    Asymptotics in Dynamics, Geometry and PDEs; Generalized Borel Summation, 2245 - 254, 2011, English, Research paper (international conference proceedings)
  • The Bender-Wu analysis and the Voros theory, II
    T. Aoki, T. Kawai, Y. Takei
    Advanced Studies in Pure Mathematics, 5419 - 94, 2009, English, Research paper (international conference proceedings)
  • Sato's conjecture for the Weber equation and transformation theory for Schrodinger equations with a merging pair of turning points
    Yoshitsugu Takei
    RIMS Kokyuroku Bessatsu, B10205 - 224, 2008, English, Research paper (international conference proceedings)
  • Half of the Toulouse Project Part 5 is completed
    T. Kawai, Y.Takei
    RIMS Kokyuroku Bessatsu, B599 - 115, 2008, English, Research paper (international conference proceedings)
  • Virtual turning points
    T.Aoki, N. Honda, T. Kawai, T. Koike, N. Nishikawa, S. Sasaki, A. Shudo, Y. Takei
    Algebraic Analysis of Differential Equations, Springer, 29 - 44, 2007, English, Research paper (scientific journal)
  • Exact WKB analysis, and exact steepest descent method --- A sequel to ``algebraic analysis for singular perturbations'' ---
    Yoshitsugu Takei
    Sugaku Expositions, 20(2)169 - 189, 2007, English, Research paper (scientific journal)
  • Toward the exact WKB analysis for instanton-type solutions of Painleve hierarchies
    Yoshitsugu Takei
    RIMS Kokyuroku Bessatsu, B2247 - 260, 2007, English, Research paper (international conference proceedings)
  • On a local reduction of a higher order Painleve equation and its underlying Lax pair near a simple turning point of the first kind
    Yoshitsugu Takei
    Seminaires et Congres, 14281 - 297, 2006, English, Research paper (international conference proceedings)
  • On global aspects of exact WKB analysis of operators admitting infinitely many phases
    T. Aoki, T. Kawai, T. Koike, Y. Takei
    Contemporary Mathematics, 37311 - 47, 2005, English, Research paper (scientific journal)
  • On the exact WKB analysis of microdifferential operators of WKB type
    T. Aoki, T. Kawai, T. Koike, Y. Takei
    Annales de l'Institut Fourier (Grenoble), 54(5)1393 - 1421, 2004, English, Research paper (scientific journal)
  • The exact steepest descent method --- a new steepest descent method based on the exact WKB analysis
    T. Aoki, T. Kawai, Y. Takei
    Advanced Studies in Pure Mathematics, 4245 - 61, 2004, English, Research paper (international conference proceedings)
  • The effect of new Stokes curves in the exact steepest descent method
    T. Koike, Y. Takei
    Microlocal Analysis and Complex Fourier Analysis, 186 - 199, 2002, English, Research paper (international conference proceedings)
  • Vanishing of Stokes curves
    T. Aoki, T. Koike, Y. Takei
    Microlocal Analysis and Complex Fourier Analysis, 1 - 22, 2002, English, Research paper (international conference proceedings)
  • Can we find a new deformation of (SLJ) with respect to the parameters contained in (PJ)?
    T. Aoki, T. Kawai, Y. Takei
    Toward the Exact WKB Analysis of Differential Equations, Linear or Non-Linear, 205 - 208, 2000, English, Research paper (international conference proceedings)
  • On a complete description of the Stokes geometry for higher order ordinary differential equations with a large parameter via integral representations
    T. Aoki, T. Kawai, Y. Takei
    Toward the Exact WKB Analysis of Differential Equations, Linear or Non-Linear, 11 - 14, 2000, English, Research paper (international conference proceedings)
  • An explicit description of the connection formula for the first Painleve equation
    Yoshitsugu Takei
    Toward the Exact WKB Analysis of Differential Equations, Linear or Non-Linear, 271 - 296, 2000, English, Research paper (international conference proceedings)
  • On the exact WKB analysis for the third order ordinary differential equations with a large parameter
    T. Aoki, T. Kawai, Y. Takei
    Asian Journal of Mathematics, 2(4)625 - 640, 1998, English, Research paper (scientific journal)
  • WKB analysis of Painleve transcendents with a large parameter, III
    T. Kawai, Y.Takei
    Advances in Mathematics, 134(1)178 - 218, 1996, English, Research paper (scientific journal)
  • On the structure of Painleve transcendents with a large parameter, II
    T. Kawai, Y.Takei
    Proceedings of the Japan Academy, Ser. A, 72(7)144 - 147, 1996, English, Research paper (scientific journal)
  • Exponential representation of a holomorphic solution of a system of differential equations associated with the theta-zerovalue
    C.A. Berenstein, T. Kawai, D.C. Struppa, Y. Takei
    Structure of Solutions of Differential Equations, 89 - 102, 1996, English, Research paper (international conference proceedings)
  • WKB analysis of Painleve transcendents with a large parameter, II
    T. Aoki, T. Kawai, Y. Takei
    Structure of Solutions of Differential Equations, 1 - 49, 1996, English, Research paper (international conference proceedings)
  • On a WKB-theoretic approach to the Painleve transcendents
    Yoshitsugu Takei
    XIth International Congress of Mathematical Physics, 533 - 542, 1995, English, Research paper (international conference proceedings)
  • Algebraic analysis of singular perturbations --- on exact WKB analysis ---
    T. Aoki, T. Kawai, Y. Takei
    Sugaku Expositions, 8(2)217 - 240, 1995, English, Research paper (scientific journal)
  • Secular equations through the exact WKB analysis
    T. Kawai, Y.Takei
    Analyse algebrique des perturbations singulieres, I., Methodes resurgentes, 85 - 102, 1994, English, Research paper (international conference proceedings)
  • New turning points in the exact WKB analysis for higher order ordinary differential equations
    T. Aoki, T. Kawai, Y. Takei
    Analyse algebrique des perturbations singulieres, I., Methodes resurgentes, 69 - 84, 1994, English, Research paper (international conference proceedings)
  • The Bender-Wu analysis and the Voros theory
    T. Aoki, T. Kawai, Y. Takei
    Special Functions, 1 - 29, 1991, English, Research paper (international conference proceedings)
  • The structure of cohomology groups associated with the theta-zerovalues
    M. Kashiwara, T. Kawai, Y. Takei
    Geometrical and Algebraical Aspects in Several Complex Variables, 169 - 189, 1991, English, Research paper (international conference proceedings)
  • The complex-analytic geometry of bicharacteristics and the semi-global existence of holomorphic solutions of linear differential equations
    T. Kawai, Y.Takei
    Geometrical and Algebraical Aspects in Several Complex Variables, 191 - 199, 1991, English, Research paper (international conference proceedings)
  • On the global existence of real analytic solutions of systems of linear differential equations
    T. Kawai, Y.Takei
    Algebraic Analysis, 331 - 344, 1988, English, Research paper (international conference proceedings)
  • Stokes geometry of higher order linear ordinary differential equations and middle convolution
    Takahiro Moteki, Yoshitsugu Takei
    ADVANCES IN MATHEMATICS, ACADEMIC PRESS INC ELSEVIER SCIENCE, 310327 - 376, Apr. 2017, English, Research paper (scientific journal)
  • On the multisummability of wkb solutions of certain singularly perturbed linear ordinary differential equations
    Yoshitsugu Takei
    Opuscula Mathematica, AGH University of Science and Technology, 35(5)775 - 802, 2015, English, Research paper (scientific journal)
  • Exact WKB analysis of a Schrodinger equation with a merging triplet of two simple poles and one simple turning point, II - Its relevance to the Mathieu equation and the Legendre equation
    Shingo Kamimoto, Takahiro Kawai, Yoshitsugu Takei
    ADVANCES IN MATHEMATICS, ACADEMIC PRESS INC ELSEVIER SCIENCE, 260565 - 613, Aug. 2014, English, Research paper (scientific journal)
  • Exact WKB analysis of a Schrodinger equation with a merging triplet of two simple poles and one simple turning point, I - Its WKB-theoretic transformation to the Mathieu equation
    Shingo Kamimoto, Takahiro Kawai, Yoshitsugu Takei
    ADVANCES IN MATHEMATICS, ACADEMIC PRESS INC ELSEVIER SCIENCE, 260458 - 564, Aug. 2014, English, Research paper (scientific journal)
  • Le prolongement analytique de la solution du problème de Cauchy pour un certain opérateur différentiel à coefficients polynomiaux III
    Yûsaku Hamada, Takashi Okaji, Yoshitsugu Takei
    Journal of Fixed Point Theory and Applications, Birkhauser Verlag AG, 14(1)149 - 163, 2013, English, Research paper (scientific journal)
  • Le prolongement analytique de la solution du problème de Cauchy pour un certain opérateur différentiel à coefficients polynomiaux II
    Yûsaku Hamada, Takashi Okaji, Yoshitsugu Takei
    Journal of Fixed Point Theory and Applications, Birkhauser Verlag AG, 14(1)113 - 148, 2013, English, Research paper (scientific journal)
  • Borel summability of the heat equation with variable coefficients
    O. Costin, H. Park, Y. Takei
    JOURNAL OF DIFFERENTIAL EQUATIONS, ACADEMIC PRESS INC ELSEVIER SCIENCE, 252(4)3076 - 3092, Feb. 2012, English, Research paper (scientific journal)
  • Microlocal analysis of fixed singularities of WKB solutions of a Schrödinger equation with a merging triplet of two simple poles and a simple turning point
    Shingo Kamimoto, Takahiro Kawai, Yoshitsugu Takei
    Springer Proceedings in Mathematics, Springer Verlag, 16125 - 150, 2012, English, Research paper (scientific journal)
  • On the exact WKB analysis of higher order simple-pole type operators
    Takahiro Kawai, Tatsuya Koike, Yoshitsugu Takei
    ADVANCES IN MATHEMATICS, ACADEMIC PRESS INC ELSEVIER SCIENCE, 228(1)63 - 96, Sep. 2011, English, Research paper (scientific journal)
  • On the Voros Coefficient for the Whittaker Equation with a Large Parameter - Some Progress around Sato's Conjecture in Exact WKB Analysis
    Tatsuya Koike, Yoshitsugu Takei
    PUBLICATIONS OF THE RESEARCH INSTITUTE FOR MATHEMATICAL SCIENCES, KYOTO UNIV, 47(1)375 - 395, Mar. 2011, English, Research paper (scientific journal)
  • WKB Analysis of Higher Order Painleve Equations with a Large Parameter. II. Structure Theorem for Instanton-Type Solutions of (P-J)(m) (J = I, 34, II-2 or IV) near a Simple P-turning Point of the First Kind
    Takahiro Kawai, Yoshitsugu Takei
    PUBLICATIONS OF THE RESEARCH INSTITUTE FOR MATHEMATICAL SCIENCES, KYOTO UNIV, 47(1)153 - 219, Mar. 2011, English, Research paper (scientific journal)
  • On the Structure of Higher Order Simple-Pole Type Operators in Exact WKB Analysis
    Takahiro Kawai, Tatsuya Koike, Yoshitsugu Takei
    FUNKCIALAJ EKVACIOJ-SERIO INTERNACIA, KOBE UNIV, DEPT MATHEMATICS, 53(2)249 - 276, Aug. 2010, English, Research paper (scientific journal)
  • On the WKB-theoretic structure of a Schrödinger operator with a merging pair of a simple pole and a simple turning point
    Shingo Kamimoto, Takahiro Kawai, Tatsuya Koike, Yoshitsugu Takei
    Kyoto Journal of Mathematics, Kyoto University, 50(1)101 - 164, 2010, English, Research paper (scientific journal)
  • Instanton-type formal solutions for the first Painlevé hierarchy
    Yoshitsugu Takei
    Algebraic Analysis of Differential Equations: From Microlocal Analysis to Exponential Asymptotics Festschrift in Honor of Takahiro Kawai, Springer Japan, 307 - 319, 2008, English
  • Virtual turning points - A gift of microlocal analysis to the exact WKB analysis
    Takashi Aoki, Naofumi Honda, Takahiro Kawai, Tatsuya Koike, Yukihiro Nishikawa, Shunsuke Sasaki, Akira Shudo, Yoshitsugu Takei
    Algebraic Analysis of Differential Equations: From Microlocal Analysis to Exponential Asymptotics Festschrift in Honor of Takahiro Kawai, Springer Japan, 29 - 43, 2008, English
  • Exact WKB analysis for the degenerate third Painleve equation of type (D-8)
    Hideaki Wakako, Yoshitsugu Takei
    PROCEEDINGS OF THE JAPAN ACADEMY SERIES A-MATHEMATICAL SCIENCES, JAPAN ACAD, 83(5)63 - 68, May 2007, English, Research paper (scientific journal)
  • Mathematical view of a blind source separation on a time frequency space
    Keiko Fujita, Yoshitsugu Takei, Akira Morimoto, Ryuichi Ashino
    APPLIED MATHEMATICS AND COMPUTATION, ELSEVIER SCIENCE INC, 187(1)153 - 162, Apr. 2007, English, Research paper (scientific journal)
  • Mathematical background for a method on quotient signal decomposition
    Ryuichi Ashino, Carlos A. Berenstein, Keiko Fujita, Akira Morimoto, Mitsuo Morimoto, Domenico Napoletani, Yoshitsugu Takei
    APPLICABLE ANALYSIS, TAYLOR & FRANCIS LTD, 86(5)577 - 609, 2007, English, Research paper (scientific journal)
  • WKB analysis of higher order Painleve' equations with a large parameter - Local reduction of 0-parameter solutions for Painleve' hierarchies (P-J) (J = I, II-1 or II-2)
    T Kawai, Y Takei
    ADVANCES IN MATHEMATICS, ACADEMIC PRESS INC ELSEVIER SCIENCE, 203(2)636 - 672, Jul. 2006, English, Research paper (scientific journal)
  • Virtual turning points and bifurcation of Stokes curves for higher order ordinary differential equations
    T Aoki, T Kawai, S Sasaki, A Shudo, Y Takei
    JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL, IOP PUBLISHING LTD, 38(15)3317 - 3336, Apr. 2005, English, Research paper (scientific journal)
  • Toward the exact WKB analysis for higher-order Painleve equations - The case of Noumi-Yamada systems
    Y Takei
    PUBLICATIONS OF THE RESEARCH INSTITUTE FOR MATHEMATICAL SCIENCES, KYOTO UNIV, 40(3)709 - 730, Sep. 2004, English, Research paper (scientific journal)
  • On WKB analysis of higher order Painleve equations with a large parameter
    T Kawai, Y Takei
    PROCEEDINGS OF THE JAPAN ACADEMY SERIES A-MATHEMATICAL SCIENCES, JAPAN ACAD, 80(5)53 - 56, May 2004, English, Research paper (scientific journal)
  • On the stokes geometry of higher order painleve equations
    T Kawai, T Koike, Y Nishikawa, Y Takei
    ASTERISQUE, SOC MATHEMATIQUE FRANCE, 297(297)117 - 166, 2004, English, Research paper (scientific journal)
  • On the exact WKB analysis of operators admitting infinitely many phases
    T Aoki, T Kawai, T Koike, Y Takei
    ADVANCES IN MATHEMATICS, ACADEMIC PRESS INC ELSEVIER SCIENCE, 181(1)165 - 189, Jan. 2004, English, Research paper (scientific journal)
  • On an exact WKB approach to Ablowitz-Segur's connection problem for the second Painleve equation
    Y Takei
    ANZIAM JOURNAL, AUSTRALIAN MATHEMATICS PUBL ASSOC INC, 44(1)111 - 119, Jul. 2002, English, Research paper (scientific journal)
  • Exact WKB analysis of non-adiabatic transition probabilities for three levels
    T Aoki, T Kawai, Y Takei
    JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL, IOP PUBLISHING LTD, 35(10)2401 - 2430, Mar. 2002, English, Research paper (scientific journal)
  • On the exact steepest descent method: A new method for the description of Stokes curves
    T Aoki, T Kawai, Y Takei
    JOURNAL OF MATHEMATICAL PHYSICS, AMER INST PHYSICS, 42(8)3691 - 3713, Aug. 2001, English, Research paper (scientific journal)
  • Singular-perturbative reduction to Birkhoff normal form and instanton-type formal solutions of Hamiltonian systems
    Y Takei
    PUBLICATIONS OF THE RESEARCH INSTITUTE FOR MATHEMATICAL SCIENCES, KYOTO UNIV, 34(6)601 - 627, Dec. 1998, English, Research paper (scientific journal)
  • WKB analysis of painlevé transcendents with a large parameter, I
    Takahiro Kawai, Yoshitsugu Takei
    Advances in Mathematics, Academic Press Inc., 118(1)1 - 33, 01 Mar. 1996, English, Research paper (scientific journal)
  • ON EXACT WKB ANALYSIS FOR PAINLEVE EQUATIONS
    Y TAKEI
    PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT, KYOTO UNIV, 116(116)311 - 317, 1994, English, Research paper (scientific journal)
  • ON THE STRUCTURE OF PAINLEVE TRANSCENDENTS WITH A LARGE PARAMETER
    T KAWAI, Y TAKEI
    PROCEEDINGS OF THE JAPAN ACADEMY SERIES A-MATHEMATICAL SCIENCES, JAPAN ACAD, 69(7)224 - 229, Sep. 1993, English, Research paper (scientific journal)
  • THE GEOMETRY OF BICHARACTERISTICS AND THE GLOBAL EXISTENCE OF HOLOMORPHIC SOLUTIONS OF SYSTEMS OF LINEAR-DIFFERENTIAL EQUATIONS
    Y TAKEI
    JOURNAL OF MATHEMATICS OF KYOTO UNIVERSITY, KINOKUNIYA CO LTD, 31(3)845 - 873, Oct. 1991, English, Research paper (scientific journal)
  • BICHARACTERISTICAL CONVEXITY AND THE SEMIGLOBAL EXISTENCE OF HOLOMORPHIC SOLUTIONS OF LINEAR-DIFFERENTIAL EQUATIONS WITH HOLOMORPHIC COEFFICIENTS
    T KAWAI, Y TAKEI
    ADVANCES IN MATHEMATICS, ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS, 80(1)110 - 133, Mar. 1990, English, Research paper (scientific journal)
  • A FINE MICROLOCALIZATION AND HYPOELLIPTICITY
    Y TAKEI
    JOURNAL OF MATHEMATICS OF KYOTO UNIVERSITY, KINOKUNIYA CO LTD, 29(1)127 - 157, Feb. 1989, English, Research paper (scientific journal)
  • ON A CLOSED RANGE PROPERTY OF A LINEAR-DIFFERENTIAL OPERATOR
    T KAWAI, Y TAKEI
    PROCEEDINGS OF THE JAPAN ACADEMY SERIES A-MATHEMATICAL SCIENCES, JAPAN ACAD, 62(10)386 - 388, Dec. 1986, English, Research paper (scientific journal)

Books etc

  • RIMS Kokyuroku Bessatsu, Vol. B61 --- Microlocal Analysis and Singular Perturbation Theory
    Y. Takei, T. Aoki, N. Honda, K. Kataoka, T. Koike
    RIMS, Kyoto University, 2017, Joint editor
  • Virtual Turning Points
    N. Honda, T. Kawai, Y. Takei
    Springer-Verlag, 2015, Joint author
  • RIMS Kokyuroku Bessatsu, Vol. B52 --- Exponential Analysis of Differential Equations and Related Topics
    Yoshitsugu Takei
    RIMS, Kyoto University, 2014, Editor
  • RIMS Kokyuroku Bessatsu, Vol. B10 --- Differential Equations and Exact WKB Analysis
    Yoshitsugu Takei
    RIMS, Kyoto University, 2008, Editor
  • Algebraic Analysis of Differential Equations --- from Microlocal Analysis to Exponential Asymptotics
    T. Aoki, H. Majima, Y. Takei, N. Tose
    Springer-Verlag, 2008, Joint editor
  • RIMS Kokyuroku Bessatsu, Vol. B2 --- Algebraic, Analytic and Geometric Aspects of Complex Differential Equations and their Deformations. Painleve Hierarchies
    Yoshitsugu Takei
    RIMS, Kyoto University, 2007, Editor
  • Algebraic Analysis of Singular Perturbation Theory
    T. Kawai, Y. Takei
    American Mathematical Society, 2005, Joint author
  • Toward the Exact WKB Analysis of Differential Equations, Linear or Non-Linear
    C.J. Howls, T. Kawai, Y. Takei
    Kyoto University Press, 2000, Joint editor

Conference Activities & Talks

  • On the instanton-type expansions for Painlevé transcendents and elliptic functions
    Yoshitsugu Takei
    Mar. 2019, English, Public lecture, seminar, tutorial, course, or other speech
  • On the instanton-type expansion of solutions and the transformation theory of differential equations
    Yoshitsugu Takei
    Jan. 2019, English, Oral presentation (invited, special)
  • Stokes phenomena and connection formulas for some discrete Painleve equations
    Yoshitsugu Takei
    Symmetries and Integrability of Difference Equations (JR Hakata City Conference Rooms, Fukuoka, Japan), Nov. 2018, English, Oral presentation (invited, special)
  • On the instanton-type expansions for Painleve transcendents and elliptic functions
    Yoshitsugu Takei
    Complex Differential and Difference Equations (Banach International Mathematical Center, Bedlewo, Poland), Sep. 2018, English, Oral presentation (invited, special)
  • On the instanton-type expansions for Painleve transcendents and elliptic functions
    Yoshitsugu Takei
    Formal and Analytic Solutions of Partial Differential Equations (University of Padova, Padova, Italy), Jun. 2018, English, Oral presentation (invited, special)
  • Stokes geometry of higher order ODEs and middle convolution
    Yoshitsugu Takei
    Asymptotic and computational aspects of complex differential equations (Centro di Ricerca Matematica Ennio De Giorgi, Pisa, Italy), Feb. 2017, English, Oral presentation (invited, special)
  • On virtual turning points --- an important ingredient of the WKB theory of higher order ODEs
    T. Kawai, Y. Takei
    Resurgence at Kavli IPMU (Kavli IPMU, University of Tokyo, Kashiwa, Japan), Dec. 2016, English, Oral presentation (invited, special)
  • On instanton-type formal solutions of singular-perturbative Hamiltonian systems with several time variables
    Yoshitsugu Takei
    Formal and Analytic Solutions of Partial Differential Equations (University of Lisbon, Lisbon, Portugal), Aug. 2016, English, Oral presentation (invited, special)
  • Exact WKB analysis for continuous and discrete Painleve equations
    Yoshitsugu Takei
    Resurgence in Gauge and String Theories (Instituto Superior Tecnico, Lisbon, Portugal), Jul. 2016, English, Oral presentation (invited, special)
  • Exact WKB analysis for continuous and discrete Painleve equations,
    Yoshitsugu Takei
    Geometry of Wall-Crossing, Deformation Quantization and Resurgent Analysis (Tohoku Forum for Creativity, Sendai, Japan), Apr. 2016, English, Oral presentation (invited, special)
  • On the exact WKB analysis of discrete Painleve equations,
    Yoshitsugu Takei
    Microlocal Analysis and Singular Perturbation Theory (RIMS, Kyoto, Japan), Oct. 2015, English, Oral presentation (invited, special)
  • WKB analysis for the discrete Painleve equation,
    Yoshitsugu Takei
    Analytic, Algebraic and Geometric Aspects of Differential Equations (Banach International Mathematical Center, Bedlewo, Poland), Sep. 2015, English, Oral presentation (invited, special)
  • WKB analysis and Stokes geometry of differential equations
    Yoshitsugu Takei
    Analytic, Algebraic and Geometric Aspects of Differential Equations (Banach International Mathematical Center, Bedlewo, Poland), Sep. 2015, English, Oral presentation (invited, special)
  • The fourth-order PI equation and coalescing phenomena of nonlinear turning points
    Yoshitsugu Takei
    Recent progress in the theory of Painleve equations: algebraic, asymptotic and topological aspects (Strasbourg, France), Nov. 2013, English, Oral presentation (invited, special)
  • On the turning point problem for Painleve equations with a large parameter
    Yoshitsugu Takei
    The 6th Pacific RIM Conference (Sapporo Convention Center, Sapporo, Japan), Jul. 2013, English, Oral presentation (invited, special)
  • On the turning point problem for instanton-type solutions of (higher order) Painleve equations
    Yoshitsugu Takei
    Asymptotics in dynamics, geometry and PDEs; generalized Borel summation (Centro di Ricerca Matematica Ennio De Giorgi, Pisa, Italy), Oct. 2009, English, Oral presentation (invited, special)
  • Instanton-type formal solutions for the first Painleve hierarchy
    Yoshitsugu Takei
    Algebraic Analysis of Differential Equations (RIMS, Kyoto, Japan), Jul. 2005, English, Oral presentation (invited, special)
  • Hierarchies of Painleve equations and exact WKB analysis
    Yoshitsugu Takei
    Theories asymptotiques et equations de Painleve (Angers, France), Jun. 2004, English, Oral presentation (invited, special)
  • A double turning point problem for systems of linear ordinary differential equations and their deformations
    Yoshitsugu Takei
    5th International Congress on Industrial and Applied Mathematics (Sydney Convention Center, Sydney, Australia), Jul. 2003, English, Oral presentation (invited, special)
  • Exact WKB analysis of non-adiabatic transition probabilities for three levels
    Yoshitsugu Takei
    Singularities, differential equations and mathematical aspects of quantum physics (Nice, France), Jul. 2002, English, Oral presentation (invited, special)
  • Exact WKB analysis and isomonodromic deformations
    Yoshitsugu Takei
    Analyzable Functions and Applications (International Centre for Mathematical Sciences, Edinburgh, UK), Jun. 2002, English, Oral presentation (invited, special)
  • Exact steepest descent method --- a discovered missing link between microlocal analysis and exact WKB analysis
    T. Aoki, T.Kawai, Y. Takei
    Memorial Conference of Kiyoshi Oka's Centennial Birthday on Complex Analysis in Several Variables (RIMS, Kyoto, Japan), Nov. 2001, English, Oral presentation (invited, special)
  • On the exact steepest descent method
    Yoshitsugu Takei
    Conference on Differential Equations in the Complex Domain (Strasbourg, France), Feb. 2001, English, Oral presentation (invited, special)
  • Connection formula for Painleve transcendents with a large parameter
    Yoshitsugu Takei
    Algebraic Analysis of Singular Perturbations (RIMS, Kyoto, Japan), Dec. 1998, English, Oral presentation (invited, special)
  • WKB analysis of Painleve transcendents with a large parameter
    T. Kawai, Y. Takei
    The 36th Taniguchi Symposium "Structure of Solutions of Differential Equations" (Otsu, Japan), Jun. 1995, English, Oral presentation (invited, special)
  • WKB analysis of Painleve transcendents
    T. Aoki, T.Kawai, Y. Takei
    Connection Problems and WKB Analysis (Isaac Newton Institute, Cambridge, UK), Mar. 1995, English, Oral presentation (invited, special)
  • Exact WKB analysis of Painleve equations
    Yoshitsugu Takei
    XIth International Congress of Mathematical Physics (UNESCO, Paris, France), Jul. 1994, English, Oral presentation (invited, special)
  • WKB analysis of ordinary differential equations of higher order
    T. Aoki, T.Kawai, Y. Takei
    Analyse algebrique des perturbations singulieres (CIRM, Marseille, France), Oct. 1991, English, Oral presentation (invited, special)

Research Grants & Projects

  • Algebraic Analysis of Singular Perturbations