10–12 Dec 2025
IBS Center for Theoretical Physics of the Universe
Asia/Seoul timezone

Generalized phyllotaxis patterns: from lattices to manifolds

12 Dec 2025, 11:30
45m
Seminar Room B440 (IBS Center for Theoretical Physics of the Universe)

Seminar Room B440

IBS Center for Theoretical Physics of the Universe

IBS Theory Building 4th Floor, 55 Expo-ro, Yuseong-gu, Daejeon, 34126, Korea
Invited speaker Day 3 Morning

Speaker

Prof. Ryoko Oishi-Tomiyasu (Kyushu University, RIKEN iTHEMS)

Description

In Turing’s study of reaction–diffusion systems, phyllotactic pattern formation was one of his motivations, especially in his later unpublished notes. His work introduced continuous and dynamic approaches to discretely given phyllotactic patterns, inspiring extensive analytical and numerical studies in reaction–diffusion systems. However, Turing himself did not investigate phyllotaxis on surfaces without rotational symmetry or in higher-dimensional spaces.
In our recent work, we propose a unified framework for generating phyllotactic point patterns on general surfaces, Euclidean spaces, and higher-dimensional manifolds with diagonalizable metrics. Our approach relies on algebraic and geometric ideas, including products of linear forms from the geometry of numbers and Lamé systems in orthogonal curvilinear coordinates, offering a complementary perspective to the continuum-based approach by Turing. This framework naturally generalizes the classical golden-angle method to more complex geometries (S. E. Graiff-Zurita & R. OT, 2024; joint work with a student in a 1-year program at Kyushu University). Time permitting, we also discuss the “missing link” between Turing’s reaction–diffusion research and discrete phyllotaxis patterns.

Presentation materials