Isostables, isochrons, and Koopman spectrum for the action–angle representation of stable fixed point dynamics

A Mauroy, I Mezić, J Moehlis - Physica D: Nonlinear Phenomena, 2013 - Elsevier
For asymptotically periodic systems, a powerful (phase) reduction of the dynamics is
obtained by computing the so-called isochrons, ie the sets of points that converge toward the …

On some open problems in planar differential systems and Hilbert's 16th problem

J Giné - Chaos, Solitons & Fractals, 2007 - Elsevier
This review paper contains a brief summary of topics and concepts related with some open
problems of planar differential systems. Most of them are related with 16th Hilbert problem …

[HTML][HTML] Complex isochronous centers and linearization transformations for cubic Z2-equivariant planar systems

F Li, Y Liu, Y Liu, P Yu - Journal of Differential Equations, 2020 - Elsevier
In this paper, we study complex isochronous center problem for cubic complex planar vector
fields, which are assumed to be Z 2-equivariant with two symmetric centers. Such integrable …

Linearizability conditions for Lotka–Volterra planar complex cubic systems

J Gine, VG Romanovski - Journal of Physics A: Mathematical and …, 2009 - iopscience.iop.org
In this paper, we investigate the linearizability problem for the two-dimensional planar
complex system. The necessary and sufficient conditions for the linearizability of this system …

[HTML][HTML] Linearizability conditions for Lotka–Volterra planar complex quartic systems having homogeneous nonlinearities

J Giné, Z Kadyrsizova, Y Liu, VG Romanovski - Computers & Mathematics …, 2011 - Elsevier
In this paper we investigate the linearizability problem for the two-dimensional Lotka–
Volterra complex quartic systems which are linear systems perturbed by fourth degree …

On commuting vector fields and Darboux functions for planar differential equations

A Ghose Choudhury, P Guha - Lobachevskii Journal of Mathematics, 2013 - Springer
We use Darboux polynomials to obtain an inverse integrating factor and present a method
for determining commuting transversal systems for a planar ordinary differential system. We …

Characterizing isochronous points and computing isochronous sections

A Algaba, M Reyes - Journal of mathematical analysis and applications, 2009 - Elsevier
We consider two-dimensional autonomous systems of differential equations where λ is a
real constant and P and Q are smooth functions of order greater than or equal to two. These …

On the critical periods of perturbed isochronous centers

A Gasull, J Yu - Journal of Differential Equations, 2008 - Elsevier
Consider a family of planar systems x˙= X (x, ε) having a center at the origin and assume that
for ε= 0 they have an isochronous center. Firstly, we give an explicit formula for the first order …

Linearizability and integrability of vector fields via commutation

J Giné, M Grau - Journal of mathematical analysis and applications, 2006 - Elsevier
In this paper, we consider complex smooth and analytic vector fields X in a neighborhood of
a nondegenerate singular point. It is proved the equivalence between linearizability and …

Isochronicity and normal forms of polynomial systems of ODEs

M Han, VG Romanovski - Journal of Symbolic Computation, 2012 - Elsevier
We propose a generalization of the notion of isochronicity for real polynomial autonomous
systems to the case of complex two dimensional systems of ODEs. We study the generalized …