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RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences Kyushu University Collaboration Team

Team Director: Ryoko Tomiyasu (Ph.D.)

Research Summary

Ryoko Tomiyasu

Our team values interdisciplinary exchange by making use of our connections with Kyushu University and the Institute of Mathematics for Industry (IMI). We are holding seminars and coding sessions to foster unexpected discoveries and opportunities for dialogue. We also engage in activities that emphasize the interface between theory and real-world applications, while maintaining a focus on deepening academic understanding.

Main Research Fields

  • Mathematical & Physical Sciences

Related Research Fields

  • Informatics
  • Interdisciplinary Science & Engineering
  • Applied mathematics
  • Algebra
  • Number theory

Keywords

  • Applied Algebra
  • Mathematical Crystallography
  • Lattices, Quadratic forms, Geometry of Numbers
  • Algorithm
  • Mathematics of Morphogenesis and Pattern Formation

Selected Publications

Papers with an asterisk(*) are based on research conducted outside of RIKEN.

  • 1. *Graiff Zurita S. E., and Oishi-Tomiyasu R.:
    "Packing theory derived from phyllotaxis and products of linear forms"
    Constructive Approximation 60, pp. 515-545 (2024).
  • 2. *Oishi-Tomiyasu, R.:
    "Ideas of lattice-basis reduction theory for error-stable Bravais lattice determination and ab-initio indexing"
    Acta Crystallographica Section A: Foundations and Advances. 80, pp. 339-350 (2024).
  • 3. *Kamaraj, R., Kane, B., and Oishi-Tomiyasu R.:
    "Universal sums of generalized heptagonal numbers"
    Journal of Number Theory 249, pp. 500—536 (2023).
  • 4. *Oishi-Tomiyasu R., Tanaka T., and Nakagawa J.:
    "Distribution rules of systematic absence and generalized de Wolff figure of merit applied to EBSD ab-initio indexing"
    Journal of Applied Crystallography 54, pp. 624—635 (2021).
  • 5. *Oishi-Tomiyasu, R.:
    "On positive-definite ternary quadratic forms with the same representations over Z"
    International Journal of Number Theory 16 (7), pp. 1493--1534 (2020).
  • 6. *Tomiyasu K., Oishi-Tomiyasu R., Matsuda M., Matsuhira M.:
    "A new mathematical approach to finding global solutions of the magnetic structure determination problem"
    Scientific Reports (2018) 8:16228.

Related Links

Lab Members

Principal investigator

Ryoko Tomiyasu
Team Director

Contact Information

Email: ryoko.tomiyasu@riken.jp

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