[HTML][HTML] Beyond the Bristol book: Advances and perspectives in non-smooth dynamics and applications

I Belykh, R Kuske, M Porfiri… - Chaos: An Interdisciplinary …, 2023 - pubs.aip.org
Non-smooth dynamics induced by switches, impacts, sliding, and other abrupt changes are
pervasive in physics, biology, and engineering. Yet, systems with non-smooth dynamics …

A review of multiple-time-scale dynamics: Fundamental phenomena and mathematical methods

KU Kristiansen - Multiplicity of Time Scales in Complex Systems …, 2023 - Springer
In this chapter, we review the most fundamental phenomena in differentiable, finite-
dimensional multiple-time-scale systems as well as the geometric singular perturbation …

Singularly perturbed boundary-equilibrium bifurcations

S Jelbart, KU Kristiansen, M Wechselberger - Nonlinearity, 2021 - iopscience.iop.org
Boundary equilibria bifurcation (BEB) arises in piecewise-smooth (PWS) systems when an
equilibrium collides with a discontinuity set under parameter variation. Singularly perturbed …

Relaxation oscillations in substrate-depletion oscillators close to the nonsmooth limit

KU Kristiansen, P Szmolyan - Nonlinearity, 2021 - iopscience.iop.org
In this paper, we describe a novel type of relaxation oscillations occurring in a model of
substrate-depletion oscillators. Using geometric singular perturbation theory, with blow-up …

[HTML][HTML] The number of limit cycles for regularized piecewise polynomial systems is unbounded

R Huzak, KU Kristiansen - Journal of Differential Equations, 2023 - Elsevier
In this paper, we extend the slow divergence-integral from slow-fast systems, due to De
Maesschalck, Dumortier and Roussarie, to smooth systems that limit onto piecewise smooth …

The Painlevé paradox in three dimensions: resolution with regularization

ND Cheesman, SJ Hogan… - Proceedings of the …, 2023 - royalsocietypublishing.org
The classical Painlevé paradox consists of a slender rigid rod slip** on a rigid rough
surface. If the coefficient of friction μ is high enough, the governing equations predict that the …

Singularly perturbed oscillators with exponential nonlinearities

S Jelbart, KU Kristiansen, P Szmolyan… - Journal of Dynamics and …, 2022 - Springer
Singular exponential nonlinearities of the form eh (x) ϵ-1 with ϵ> 0 small occur in many
different applications. These terms have essential singularities for ϵ= 0 leading to very …

A stiction oscillator with canards: on piecewise smooth nonuniqueness and its resolution by regularization using geometric singular perturbation theory

E Bossolini, M Brøns, KU Kristiansen - SIAM Review, 2020 - SIAM
In mechanics, one often describes microscopic processes such as those leading to friction
between relative interfaces using macroscopic variables (relative velocity, temperature, etc.) …

Traveling Waves and Exponential Nonlinearities in the Zeldovich–Frank-Kamenetskii Equation

S Jelbart, KU Kristiansen, P Szmolyan - SIAM Journal on Applied Dynamical …, 2025 - SIAM
We prove the existence of a family of traveling wave solutions in a variant of the Zeldovich–
Frank-Kamenetskii (ZFK) equation, a reaction-diffusion equation which models the …

On a tropicalization of planar polynomial ODEs with finitely many structurally stable phase portraits

KU Kristiansen, AH Sarantaris - arxiv preprint arxiv:2305.18002, 2023 - arxiv.org
Recently, concepts from the emerging field of tropical geometry have been used to identify
different scaling regimes in chemical reaction networks where dimension reduction may take …