Characterization of centers by its complex separatrices

IA García, J Giné - arXiv preprint arXiv:2412.09197, 2024 - arxiv.org
In this work we deal with analytic families of real planar vector fields $\mathcal {X} _\lambda
$ having a monodromic singularity at the origin for any $\lambda\in\Lambda\subset\mathbb …

Principal Bautin ideal of monodromic singularities with inverse integrating factors

IA García, J Giné - arXiv preprint arXiv:2412.09205, 2024 - arxiv.org
We analyze the structure of the Poincar\'e map $\Pi $ associated to a monodromic singularity
of an analytic family of planar vector fields. We work under two assumptions. The first one is …

[HTML][HTML] Center conditions to find certain degenerate centers with characteristic directions

A Algaba, C García, J Giné - Mathematics and Computers in Simulation, 2024 - Elsevier
We consider the two-dimensional autonomous systems of differential equations where the
origin is a monodromic degenerate singular point, ie, with null linear part. In this work we …

Existence and nonexistence of Puiseux inverse integrating factors in analytic monodromic singularities

IA García, J Giné, AL Rodero - Studies in Applied Mathematics, 2024 - Wiley Online Library
In this work, we present some criteria about the existence and nonexistence of both Puiseux
inverse integrating factors VV and Puiseux first integrals HH for planar analytic vector fields …

The Poincaré map of degenerate monodromic singularities with Puiseux inverse integrating factor

IA García, J Giné - Advances in Nonlinear Analysis, 2023 - degruyter.com
We consider analytic families of planar vector fields depending analytically on the
parameters in Λ that guarantee the existence of a (may be degenerate and with …

[HTML][HTML] The center problem for Z2-symmetric nilpotent vector fields

A Algaba, C García, J Giné, J Llibre - Journal of Mathematical Analysis and …, 2018 - Elsevier
We say that a polynomial differential system x˙= P (x, y), y˙= Q (x, y) having the origin as a
singular point is Z 2-symmetric if P (− x,− y)=− P (x, y) and Q (− x,− y)=− Q (x, y). It is known …

[HTML][HTML] The center problem. A view from the normal form theory

A Algaba, E Gamero, C García - Journal of Mathematical Analysis and …, 2016 - Elsevier
In this work, we analyze some aspects of the center problem from the perspective of the
normal form theory. We provide alternative proofs of some well known results in the case of …

Characterization of global centers by the monodromy at infinity

IA García, J Giné, J Llibre - … in Nonlinear Science and Numerical Simulation, 2025 - Elsevier
In this work we focus in the family of real planar polynomial vector fields of arbitrary degree.
We are interested in to characterize when a (local) center singularity of these vector fields …

Establishing definitive conditions for monodromic equilibria and centers of continuous piecewise linear systems with arbitrary finite number of switching lines

H Chen, D Dai, L Liu, L Zou - Journal of Differential Equations, 2025 - Elsevier
This paper aims to provide sufficient and necessary conditions for the monodromic problem
and center problem of continuous piecewise linear systems with arbitrary finite number of …

Geometric criterium in the center problem

A Algaba, C García, J Giné - Mediterranean Journal of Mathematics, 2016 - Springer
In this paper, we use a geometric criterium based on the classical method of the construction
of Lyapunov functions to determine if a differential system has a focus or a center at a …