\(QS91_{2}^{(2)}\)
Description
Phase Portrait
Topological Invariants
| TCSP | Fin Sep | Inf Sep |
|---|---|---|
| \(91\) | \(1\) | \(4111\) |
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 \(U^2_{BC,25}\) in Missing reference in BC1Note (for name \(U^2_{BC,25}\)): The system has 1 limit cycle.
- With names \(B V14\) and \(B V16\) in {J. C. Artés, M. C. Mota and A. C. Rezende}, Quadratic systems possessing an infinite elliptic-saddle or an infinite nilpotent saddle, Internat. J. Bifur. Chaos Appl. Sci. Engrg. { bf 34} (2024), no.~11, Paper No. 2430023, 43 pp.; MR4801966Note (for name \(B V16\)): The system has 1 limit cycle.
- With names \(fig 5.04(d)\) and \(fig 5.04(h)\) in {B. Coll, A. Gasull and J. Llibre}, Quadratic systems with a unique finite rest point, emph{Publ. Mat.}, textbf{32} (1988), 199--259.Note (for name \(fig 5.04(d)\)): The system has 1 limit cycle.
- With names \(Fig10.3 (10)\), \(Fig11.1 (5)\), \(Fig11.3c (3)\), \(Fig11.3c (7)\) and \(Fig11.3c (8)\) in {J. W. Reyn and X. H. Huang}, Phase portraits of quadratic systems with finite multiplicity three and a degenerate critical point at infinity, Rocky Mountain J. Math. { bf 27} (1997), no.~3, 929--978; MR1490285Note (for name \(Fig11.3c (7)\)): separatrices too shortNote (for name \(Fig11.3c (7)\)): The system has 1 limit cycle.Note (for name \(Fig11.3c (8)\)): separatrices too short
- With names \(QS91_{2}^{(2)}\) and \(QS91_{2}^{(2)}\) in {J. C. Artés, J. Llibre, D. Schlomiuk and N. Vulpe}, Phase portraits of a family of real quadratic differential systemspossessing a nilpotent or intricate singularity at infinity, {Preprint} (2026).Note (for name \(QS91_{2}^{(2)}\)): The system has 1 limit cycle.