Electron. J. Differential Equations, Vol. 2024 (2024), No. 50, pp. 1-38.

Abel quadratic differential systems of second kind

Joan C. Artes, Jaume Llibre, Dana Schlomiuk, Nicolae Vulpe

Abstract:
The Abel differential equations of second kind, named after Niels Henrik Abel, are a class of ordinary differential equations studied by many authors. Here we consider the Abel quadratic polynomial differential equations of second kind denoting this class by \(QS_{Ab}\). Firstly we split the whole family of non-degenerate quadratic systems in four subfamilies according to the number of infinite singularities. Secondly for each one of these four subfamilies we determine necessary and sufficient affine invariant conditions for a quadratic system in this subfamily to belong to the class \(QS_{Ab}\). Thirdly we classify all the phase portraits in the Poincaré disc of the systems in \(QS_{Ab}\) in the case when they have at infinity either one triple singularity (21 phase portraits) or an infinite number of singularities (9 phase portraits). Moreover we determine the affine invariant criteria for the realization of each one of the 30 topologically distinct phase portraits.

Submitted July 10, 2024. Published September 4, 2024.
Math Subject Classifications: 58K45, 34C23, 34A34.
Key Words: Quadratic differential systems; phase portraits; second kind of Abel differential equations; affine invariant polynomials.
DOI: 10.58997/ejde.2024.50

Show me the PDF file (668 KB), TEX file for this article.

Joan C. Artés
Departament de Matemátiques
Universitat Autónoma de Barcelona
08193 Bellaterra, Barcelona, Spain
email: joancarles.artes@uab.cat
Jaume Llibre
Departament de Matemátiques
Universitat Autónoma de Barcelona
08193 Bellaterra, Barcelona, Spain
email: jaume.llibre@uab.cat
Dana Schlomiuk
Département de Mathématiques et de Statistiques
Université de Montréal
Montreal, Canada
email: dana.schlomiuk@umontreal.ca
Nicolae Vulpe
Institute of Mathematics and Computer Science
Academy of Science of Moldova
5 Academiei str, Chisnau, MD-2028, Moldova
email: nvulpe@gmail.com

Return to the EJDE web page