\(QS27_{7}^{(2)}\)
Description
Phase Portrait
Topological Invariants
| TCSP | Fin Sep | Inf Sep |
|---|---|---|
| \(27\) | \(41\) | \(2120\) |
Example
The quadratic differential system
\[\begin{cases} \dot{x} = 2 \, ch \, x \, y + (-1 - 2 \, ch) \, y^{2} \\ \dot{y} = cl \, x^{2} + y + (1 + 2 \, ch - 2 \, cl) \, x \, y + (2 \, (-1 - 2 \, ch) + 2 \, ch + cl) \, y^{2} \end{cases}\]
has the following phase portrait done with P4. If you want, you may download the P4 file here.
The phase portrait appears in the following papers
- With name \(BD08\) in {J. C. Artés}, Systems of class BD, {Preprint} (2026).
- With name \(5.7L3\) in {J. C. Artés, R. D. S. Oliveira and A. C. Rezende}, Topological classification of quadratic polynomial differential systems with a finite semi-elemental triple saddle, Internat. J. Bifur. Chaos Appl. Sci. Engrg. { bf 26} (2016), no.~11, 1650188, 26 pp.; MR3566296
- With name \(Fig 1.7 h\) in {J. W. Reyn and R. E. Kooij}, Phase portraits of non-degenerate quadratic systems with finite multiplicity two, Differential Equations Dynam. Systems { bf 5} (1997), no.~3-4, 355--414; MR1660222Note (for name \(Fig 1.7 h\)): one wrong separatrix
- With name \(2.7L17\) 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.