Pinned solutions in a heterogeneous three-component FitzHugh–Nagumo model

P van Heijster, CN Chen, Y Nishiura… - Journal of Dynamics and …, 2019 - Springer
We analyse pinned front and pulse solutions in a singularly perturbed three-component
FitzHugh–Nagumo model with a small jump-type heterogeneity. We derive explicit …

Hamiltonian Spectral Flows, the Maslov Index, and the Stability of Standing Waves in the Nonlinear Schrodinger Equation

G Cox, M Curran, Y Latushkin, R Marangell - SIAM Journal on Mathematical …, 2023 - SIAM
We use the Maslov index to study the spectrum of a class of linear Hamiltonian differential
operators. We provide a lower bound on the number of positive real eigenvalues, which …

Stability of stationary fronts in a non-linear wave equation with spatial inhomogeneity

CJK Knight, G Derks, A Doelman, H Susanto - Journal of Differential …, 2013 - Elsevier
We consider inhomogeneous non-linear wave equations of the type utt= uxx+ V′(u, x)− αut
(α⩾ 0). The spatial real axis is divided in intervals Ii, i= 0,…, N+ 1 and on each individual …

A geometric approach to stationary defect solutions in one space dimension

A Doelman, P van Heijster, F Xie - SIAM Journal on Applied Dynamical …, 2016 - SIAM
In this manuscript, we consider the impact of a small jump-type spatial heterogeneity on the
existence of stationary localized patterns in a system of partial differential equations in one …

Pulse dynamics in reaction–diffusion equations with strong spatially localized impurities

A Doelman, P Van Heijster… - … Transactions of the …, 2018 - royalsocietypublishing.org
In this article, a general geometric singular perturbation framework is developed to study the
impact of strong, spatially localized, nonlinear impurities on the existence, stability and …

Symmetry breaking bifurcations in the NLS equation with an asymmetric delta potential

R Rusin, R Marangell, H Susanto - Nonlinear Dynamics, 2020 - Springer
We consider the NLS equation with a linear double-well potential. Symmetry breaking, ie the
localisation of an order parameter in one of the potential wells that can occur when the …

Dark solitons near potential and nonlinearity steps

F Tsitoura, ZA Anastassi, JL Marzuola, PG Kevrekidis… - Physical Review A, 2016 - APS
We study dark solitons near potential and nonlinearity steps and combinations thereof,
forming rectangular barriers. This setting is relevant to the contexts of atomic Bose-Einstein …

An instability criterion for nonlinear standing waves on nonzero backgrounds

RK Jackson, R Marangell, H Susanto - Journal of Nonlinear Science, 2014 - Springer
A nonlinear Schrödinger equation with repulsive (defocusing) nonlinearity is considered. As
an example, a system with a spatially varying coefficient of the nonlinear term is studied. The …

Stability of fronts in inhomogeneous wave equations

G Derks - Acta Applicandae Mathematicae, 2015 - Springer
This paper presents an introduction to the existence and stability of stationary fronts in wave
equations with finite length spatial inhomogeneities. The main focus will be on wave …

[PDF][PDF] Hamiltonian spectral theory and the Maslov index

M Curran - 2024 - maths.usyd.edu.au
A central theme underpinning this thesis is “a beautiful connection between analysis,
dynamics and topology"[Bec20], which can be found in the 19th century Sturmian theory of …