Center for Mathematical Science and Advanced Technology (MAT)

Seminar Schedule

[MAT Seminar]

Date:

2026/03/11(Wednesday) 13:00-15:00

Language:

English

Venue:

MAT Theater, 508, IT5F, YES & Zoom (Hybrid)

Speaker:

Riccardo Muolo (RIKEN iTHEMS)

Title:

A parametrization method for higher-order phase reduction: effects of non-pairwise interactions on synchronization dynamics and synchronization engineering

Abstract:

A parametrization method for higher-order phase reduction to understand the effects of non-pairwise interactions on synchronization dynamics. Recent studies have shown that non-pairwise interactions play a crucial role in shaping synchronization dynamics. Such interactions can have different origins. For instance, in systems with physical states xk, xj, xl ∈ ℝ, a non-pairwise coupling may take the form G(xk, xj, xl) = xk xj xl, whereas in phase models with θk, θj, θl ∈ 𝕋, it may appear as g(θk, θj, θl) = sin(θk+θj - 2θl). The link between such physical and phase-level interactions is established through phase reduction for weakly coupled oscillators, generally expressed as an asymptotic expansion in the coupling strength ε. Classical first-order phase reductions, such as the Kuramoto one, capture only pairwise interactions, but higher-order reductions, such as the León and Pazó one, reveal the emergence of non-pairwise terms. These can arise either directly from nonpairwise couplings in the physical variables or at higher orders even when the physical coupling is pairwise. Here, we employ a parametrization-based method for higher-order phase reduction that captures both routes simultaneously by approximating an invariant torus in the full system phase space, providing a unified description of nonpairwise synchronization dynamics. Then, we use such result to "hack" the phase model to obtain the desired dynamics, through a synchronization engineering approach.

[MAT Seminar]

Date:

2026/03/04(Wednesday) 13:00-15:00

Language:

English

Venue:

MAT Theater, 508, IT5F, YES & Zoom (Hybrid)

Speaker:

Ettore Barbieri (MAT)

Title:

Curvami: an open-source software for curved origami

Abstract:

Origami-inspired design has cultivated a rich ecosystem of computational tools. However, while widely used kinematics-based programs efficiently handle the design of flat- and rigid-foldable patterns, simulating the physical reality of non-rigid curved origami remains a severe computational challenge. Structural analysis typically relies on finite element methods (FEM), but these frameworks face significant hurdles when dealing with curved creases and nonlinear plate theories. Meshing complex curved folds routinely forces degenerate topologies and restrictive element continuity requirements that hinder accurate nonlinear analysis.
To overcome these limitations, we present Curvami, an open-source meshless simulation framework. Curvami employs Moving Least Squares (MLS) approximations to construct smooth, high-order basis functions. Because meshfree approaches are not restricted by element shape or nodal connectivity, this method allows complex creases to float arbitrarily across the integration domain without requiring destructive boolean meshing.
The formulation couples differential geometry with continuum mechanics, accounting for large displacements, rotations, and extreme spatial curvatures. Furthermore, because curved folds are inherently prone to geometric frustration and violent structural bifurcations—such as snap-through and snap-back instabilities—we detail the robust numerical machinery required to solve these highly constrained systems. By pairing a Nullspace Projected Line Search Newton-Raphson solver with an Arc-Length method, the framework reliably traces highly complex equilibrium paths.

[MAT Seminar]

Date:

2026/02/25(Wednesday) 13:00-15:00

Language:

English

Speaker:

Jian Chen (MAT)

[MAT Seminar]

Date:

2026/02/18(Wednesday) 13:00-15:00

Language:

Japanese

Speaker:

Daisuke Nishiura (MAT)

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