We know five different families of algebraic limit cycles in quadratic systems, one of degree 2 and four of degree 4. Moreover, if there are other families of algebraic limit cycles for quadratic systems, then their degrees must be larger than 4. It is known that if a quadratic system has an algebra
Limit cycles of quadratic systems
β Scribed by Valery A. Gaiko
- Publisher
- Elsevier Science
- Year
- 2008
- Tongue
- English
- Weight
- 266 KB
- Volume
- 69
- Category
- Article
- ISSN
- 0362-546X
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β¦ Synopsis
In this paper, the global qualitative analysis of planar quadratic dynamical systems is established and a new geometric approach to solving Hilbert's Sixteenth Problem in this special case of polynomial systems is suggested. Using geometric properties of four field rotation parameters of a new canonical system which is constructed in this paper, we present a proof of our earlier conjecture that the maximum number of limit cycles in a quadratic system is equal to four and their only possible distribution is (3:1) [V. A. Gaiko, Global Bifurcation Theory and Hilbert's Sixteenth Problem, Kluwer, Boston, 2003]. Besides, applying the Wintner-Perko termination principle for multiple limit cycles to our canonical system, we prove in a different way that a quadratic system has at most three limit cycles around a singular point (focus) and give another proof of the same conjecture.
π SIMILAR VOLUMES
a b s t r a c t Like for smooth quadratic systems, it is important to determine the maximum order of a fine focus and the cyclicity of discontinuous quadratic systems. Previously, examples of discontinuous quadratic systems with five limit cycles bifurcated from a fine focus of order 5 have been con
In this paper a class of quadratic systems is studied. By quadratic systems we mean autonomous quadratic vector fields in the plane. The class under consideration is class \(\mathrm{II}_{n=0}\) in the Chinese classification of quadratic systems. Bifurcation sets \(\delta=\delta^{*}(l, m)(m>2, l>0)\)
A method for the asymptotic integration of the trajectories is proposed for the LiΓ©nard equation. The results obtained by this method are used to prove the existence of two "large" limit cycles in quadratic systems with a weak focus. The application of standard procedures of small perturbations of t