RUS  ENG
Full version
JOURNALS // Buletinul Academiei de Ştiinţe a Republicii Moldova. Matematica // Archive

Bul. Acad. Ştiinţe Repub. Mold. Mat., 2003 Number 1, Pages 31–46 (Mi basm185)

This article is cited in 10 papers

Research articles

Quadratic systems with limit cycles of normal size

Leonid A. Cherkasa, Joan C. Artésb, Jaume Llibreb

a Belarusian State University of Informatics and Radioelectronics, Minsk, Belarus
b Departament de Matemàtiques, Universitat Autònoma de Barcelona, Barcelona, Spain

Abstract: In the class of planar autonomous quadratic polynomial differential systems we provide 6 different phase portraits having exactly 3 limit cycles surrounding a focus, 5 of them have a unique focus. we also provide 2 different phase portraits having exactly 3 limit cycles surrounding one focus and 1 limit cycle surrounding another focus. the existence of the exact given number of limit cycles is proved using the dulac function. all limit cycles of the given systems can be detected through numerical methods; i.e. the limit cycles have “a normal size” using perko's terminology.

Keywords and phrases: quadratic systems, limit cycles.

MSC: 34C07, 34C08

Received: 18.10.2002

Language: English



Bibliographic databases:


© Steklov Math. Inst. of RAS, 2024