\(QS1_{1}^{(2)}\)
Description
Phase Portrait
Topological Invariants
| TCSP | Fin Sep | Inf Sep |
|---|---|---|
| \(1\) | \(4441\) | \(211111\) |
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 \(DD01\) in {J. C. Artés}, Systems of class DD, {Preprint} (2026).
- With name \(3.1(a2)\) in {D. Schlomiuk and N. Vulpe}, Global classification of the planar Lotka--Volterra differential systems according to their configurations of invariant straight lines, emph{J. Fixed Point Theory Appl.}, { bf 8}, no. 1 (2010), 177--245.
- With names \(Fig. 1 02\), \(Fig. 1 07\), \(Fig. 1 14\), \(Fig. 1 19\), \(Fig. 4 2\), \(Fig. 4 7\), \(Fig. 5 2\), \(Fig. 5 6\), \(Fig. 6 2\), \(Fig. 6 7\), \(Fig. 7 2\), \(Fig. 7 7\), \(Fig. 8 2\), \(Fig. 8 6\), \(Fig. 9 2\) and \(Fig. 9 7\) in {P. C. Carri\~ao, M. E. S. Gomes and A. A. G. Ruas}, Planar quadratic vector fields with finite saddle connection on a straight line (non-convex case), Qual. Theory Dyn. Syst. { bf 7} (2009), no.~2, 417--433; MR2486684
- With names \(Fig 2A Ia\) and \(Fig 2A Ic\) in {J. W. Reyn}, Phase portraits of a quadratic system of differential equations occurring frequently in applications, emph{Nieuw Arch. Wisk. (4)}, textbf{5}, no. 2 (1987), 107--151.
- With name \(b\) in {A. Zegeling}, Quadratic systems with three saddles and one antisaddle, Delft University of Technology, Faculty of Technical Mathematics and Informatics, Report 80 (1989).