\(QS32_{15}^{(3)}\)
Description
Topological configuration of singularities: \(a,a,sn;S,(0,2)SN\)
Phase Portrait
Topological Invariants
| TCSP | Fin Sep | Inf Sep |
| \(32\) | \(431\) | \(1111\) |
Example
The quadratic differential system
\[\begin{cases} \dot{x} = P_x(x,y) \\ \dot{y} = P_y(x,y) \end{cases}\]
has the following phase portrait done with P4.
The phase portrait appears in the following papers
- With name \(4.5L4\) in {J. C. Artés and C. Trullàs}, Quadratic Differential Systems with a Weak Focus of First-Order and a Finite Saddle-Node, {International Journal of Bifurcation and Chaos, Vol. 36, No. 6 (2026) 2630013 (99 pages)}
- With name \(2.5L4\) in {J. C. Artés, J. Llibre and D. Schlomiuk}, The geometry of quadratic polynomial differential systems with a weak focus and an invariant straight line, emph{ Internat. J. Bifur. Chaos Appl. Sci. Engrg.}, textbf{20}, no. 11 (2010), 3627--3662.
- With name \(Fig3 V6\) in {J. C. Artés, A. C. Rezende and R. Oliveira}, The geometry of quadratic polynomial differential systems with a finite and an infinite saddle-node (A,B), emph{Internat. J. Bifur. Chaos Appl. Sci. Engrg.}, textbf{24}, no. 4 (2014), 1450044, 30 pp.
- With names \(4S15\) and \(4S25\) in {J. C. Artés, A. C. Rezende and R. D. S. Oliveira}, The geometry of quadratic polynomial differential systems with a finite and an infinite saddle-node (C), emph{Internat. J. Bifur. Chaos Appl. Sci. Engrg.}, textbf{25}, no. 3 (2015), 1530009, 111 pp.Note (for name \(4S25\)): The system has limit cycles with distribution \((0,1)\).
Comments
This phase portrait appears in J. C. Artés and C. Trullàs ({International Journal of Bifurcation and Chaos, Vol. 36, No. 6 (2026) 2630013 (99 pages)}) featuring a weak focus of first order. Consequently, a configuration structurally equivalent to \(QS32_{15}^{(3)}\) could potentially exhibit an additional limit cycle bifurcating from the focus.