\(QS28_{1}^{(1)}\)
Description
Topological configuration of singularities: \(s,s,sn;N,N,N\)
Phase Portrait
Topological Invariants
| TCSP | Fin Sep | Inf Sep |
| \(28\) | \(544\) | \(212121\) |
Example
The quadratic differential system
\[\begin{cases} \dot{x} = -x-x^{2}-(2+2 \, x) \, y+e \, x^{2} \\ \dot{y} = x \, y+y^{2}+d \, x^{2} \end{cases}\]
with parameters: \(e = 0.1, \quad d = 0.01\)
has the following phase portrait done with P4. If you want, you may download the P4 file here. Since the image is not clear enough, we have added a ZOOM of it.
The phase portrait appears in the following papers
- With name \(9\) in {A. Ferragut, J. D. García-Saldaña and C. Valls}, Phase portraits of Abel quadratic differential systems of second kind with symmetries, Dyn. Syst. { bf 34} (2019), no.~2, 301--333; MR3941199
- With name \(U^1_{A14}\) in {J. C. Artés, J. Llibre and A. C. Rezende}, Structurally unstable quadratic vector fields of codimension one, Birkhäuser/Springer, Cham, 2018, vi+267 pp.
Bifurcations in codimension 0