Abstract
We consider the problem of distinguishing the center and focus in the case of a “strongly degenerate” singular point. A sufficient condition is explicitly stated for the existence of a focus for singular points of vector fields on the plane belonging to a certain class.
Similar content being viewed by others
Literature cited
V. V. Nemytskii and V. V. Stepanov, Qualitative Theory of Differential Equations [in Russian], Gostekhizdat, Moscow-Leningrad (1947).
A. M. Lyapunov, General Problem of the Stability of Motion [in Russian], Gostekhizdat, Moscow-Leningrad (1950).
A. D. Bryuno, A Local Method of Nonlinear Analysis for Differential Equations [in Russian], Nauka, Moscow (1979).
I. Bendixon, “Sur les courbes definies par des equations differentielles,” Acta Math.,24, 1–88 (1901).
F. Dumortier, “Singularities of vector fields on the plane,” J. Dif. Eq.,23, 53–106 (1977).
F. Takens, “Singularities of vector fields,” Publ. Math. I.H.E.S.,43, 47–100 (1974).
Yu. S. Il'yashenko, “Singular points and limit cycles of differential equations on the real and complex plane,” Preprint ONTI NTsBI Academy of Sciences of the USSR, Pushchino (1982).
V. I. Arnol'd, Supplementary Chapters to the Theory of Ordinary Differential Equations [in Russian], Nauka, Moscow (1978).
H. Dulac, Limit Cycles [Russian translation], Nauka, Moscow (1980).
V. P. Nozdracheva, “A congruence function in a neighborhood of a structurally stable saddle,” Diff. Urav.,15, No. 2, 252–261 (1979).
R. I. Bogdanov, “Local orbital normal forms of vector fields on the plane,” Trudy sem. im. U. G. Petrovskogo, No. 5, 51–84 (1979).
K. T. Chen, “Equivalence and decomposition of vector fields about an elementary critical point,” Am. J. Math.,85, 693–722 (1963).
Additional information
Translated from Trudy Seminara imeni I. G. Petrovskogo, No. 13, pp. 106–122, 1988.
Rights and permissions
About this article
Cite this article
Medvedeva, N.B. The first focus quantity of a complex monodromic singular point. J Math Sci 50, 1421–1436 (1990). https://doi.org/10.1007/BF01097031
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01097031