Birkhoff averages and rotational invariant circles for area-preserving maps

E Sander, JD Meiss - Physica D: Nonlinear Phenomena, 2020 - Elsevier
Rotational invariant circles of area-preserving maps are an important and well-studied
example of KAM tori. John Greene conjectured that the locally most robust rotational circles …

Birkhoff averages and the breakdown of invariant tori in volume-preserving maps

JD Meiss, E Sander - Physica D: Nonlinear Phenomena, 2021 - Elsevier
In this paper, we develop numerical methods based on the weighted Birkhoff average for
studying two-dimensional invariant tori for volume-preserving maps. The methods do not …

Polar rotation angle identifies elliptic islands in unsteady dynamical systems

M Farazmand, G Haller - Physica D: Nonlinear Phenomena, 2016 - Elsevier
We propose rotation inferred from the polar decomposition of the flow gradient as a
diagnostic for elliptic (or vortex-type) invariant regions in non-autonomous dynamical …

Using rotation number to detect sticky orbits in Hamiltonian systems

MS Santos, M Mugnaine, JD Szezech… - … Journal of Nonlinear …, 2019 - pubs.aip.org
In Hamiltonian systems, depending on the control parameter, orbits can stay for very long
times around islands, the so-called stickiness effect caused by a temporary trapping …

Coherent transport structures in magnetized plasmas. I. Theory

G Di Giannatale, MV Falessi, D Grasso… - Physics of …, 2018 - pubs.aip.org
In a pair of linked articles (called Papers I and II, respectively), we apply the concept of
Lagrangian Coherent Structures (LCSs) borrowed from the study of dynamical systems to …

Predictability of orbits in coupled systems through finite-time Lyapunov exponents

JC Vallejo, MAF Sanjuan - New Journal of Physics, 2013 - iopscience.iop.org
The predictability of an orbit is a key issue when a physical model has strong sensitivity to
the initial conditions and it is solved numerically. How close the computed chaotic orbits are …

[HTML][HTML] Quantifying the tangling of trajectories using the topological entropy

S Candelaresi, DI Pontin, G Hornig - Chaos: An Interdisciplinary …, 2017 - pubs.aip.org
We present a simple method to efficiently compute a lower limit of the topological entropy
and its spatial distribution for two-dimensional mappings. These mappings could represent …

Measure, dimension, and complexity of the transient motion in Hamiltonian systems

VM de Oliveira, MS Palmero, IL Caldas - Physica D: Nonlinear Phenomena, 2022 - Elsevier
Hamiltonian systems that are either open, leaking, or contain holes in the phase space
possess solutions that eventually escape the system's domain. The motion described by …

Novel gradient calculation method for the largest Lyapunov exponent of chaotic systems

H Liao - Nonlinear Dynamics, 2016 - Springer
A novel method is presented to calculate the sensitivity gradients of the largest Lyapunov
exponent (LLE) in dynamical systems. After the elimination of the discontinuity of state …

[HTML][HTML] Unpredictability in Hamiltonian systems with a hierarchical phase space

MR Sales, M Mugnaine, RL Viana, IL Caldas… - Physics Letters A, 2022 - Elsevier
One of the main consequences of the complex hierarchical structure of chaotic regions and
stability islands in the phase space of a typical nonlinear Hamiltonian system is the …