Citation: |
[1] |
A. Algaba and M. Reyes, Computing center conditions for vector fields with constant angular speed, J. Comput. Appl. Math., 154 (2003), 143-159.doi: 10.1016/S0377-0427(02)00818-X. |
[2] |
-, Centers with degenerate infinity and their commutators, J. Math. Anal. Appl., 278 (2003), 109-124.doi: 10.1016/S0022-247X(02)00625-X. |
[3] |
A. Algaba, M. Reyes, A. Bravo and T. Ortega, Campos cuárticos con velocidad angular constante, in Actas del XVI CEDYA '99, (1999), 1339-1340. |
[4] |
A. Algaba, M. Reyes and A. Bravo, Uniformly isochronous quintic planar vector fields, International Conference on Differential Equations, (Berlin, 1999), World Sci. Publ., River Edge, NJ, 1/2 (2000), 1415-1417. http://dynamics.mi.fu-berlin.de/equadiff/. |
[5] |
M. A. M. Alwash, On the center conditions of certain cubic systems, Proc. Amer. Math. Soc., 126 (1998), 3335-3336.doi: 10.1090/S0002-9939-98-04715-7. |
[6] |
I. Bendixson, Sur les courbes définies par des équations différentielles (French), Acta Math., 24 (1901), 1-88.doi: 10.1007/BF02403068. |
[7] |
J. Chavarriga, I. A. García and J. Giné, On integrability of differential equations defined by the sum of homogeneous vector fields with degenerate infinity, Internat. J. Bifur. Chaos Appl. Sci. Engrg., 11 (2001), 711-722.doi: 10.1142/S0218127401002390. |
[8] |
C. B. Collins, Algebraic conditions for a centre or a focus in some simple systems of arbitrary degree, J. Math. Anal. Appl., 195 (1995), 719-735.doi: 10.1006/jmaa.1995.1385. |
[9] |
-, Conditions for a centre in a simple class of cubic systems, Differential Integral Equations, 10 (1997), 333-356. http://projecteuclid.org/euclid.die/1367526341 |
[10] |
R. Conti, Uniformly Isochronous Centers of Polynomial Systems in $\mathbbR^2$, Lecture Notes in Pure and Appl. Math., 152, Dekker, New York, 1994, (Differential equations, dynamical systems, and control science, 21-31). |
[11] |
A. Cima, A. Gasull and F. Mañosas, Cyclicity of a family of vector fields, J. Math. Anal. Appl., 196 (1995), 921-937.doi: 10.1006/jmaa.1995.1451. |
[12] |
F. S. Dias and L. F. Mello, The center-focus problem and small amplitude limit cycles in rigid systems, Discrete Contin. Dyn. Syst., 32 (2012), 1627-1637.doi: 10.3934/dcds.2012.32.1627. |
[13] |
H. Dulac, Détermination et intégration d'une certaine classe d'quations diffŕentielles ayant pour point singulier un centre, Bull. Sci. Math Sér. (2), 32 (1908), 230-252. |
[14] |
W. W. Farr, Li. Chengzhi, I. S. Labouriau and W. F. Langford, Degenerate Hopf bifurcation formulas and Hilbert's 16th problem, SIAM J. Math. Anal., 20 (1989), 13-30.doi: 10.1137/0520002. |
[15] |
M. Frommer, Über das Auftreten von Wirbeln und Strudeln (geschlossener und spiraliger Integralkurven) in der Umgebung rationaler Unbestimmtheitsstellen, Math. Ann., 109 (1934), 395-424.doi: 10.1007/BF01449147. |
[16] |
A. Gasull, A. Guillamon and V. Mañosa, An explicit expression of the first Liapunov and period constants with applications, J. Math. Anal. Appl., 211 (1997), 190-212.doi: 10.1006/jmaa.1997.5455. |
[17] |
A. Gasull and J. Torregrosa, Exact number of limit cycles for a family of rigid systems, Proc. Amer. Math. Soc., 133 (2005), 751-758.doi: 10.1090/S0002-9939-04-07542-2. |
[18] |
A. Gasull, R. Prohens and J. Torregrosa, Limit cycles for rigid cubic systems, J. Math. Anal. Appl., 303 (2005), 391-404.doi: 10.1016/j.jmaa.2004.07.030. |
[19] |
W. Kapteyn, On the midpoints of integral curves of differential equations of the first degree (Dutch), Nederl. Akad. Wetensch. Verslag Afd. Natuurk. Konikl. Nederland, 19 (1911), 1446-1447. |
[20] |
-, New investigations on the midpoints of integral curves of differential equations of the first degree (Dutch) Nederl. Akad. Wetensch. Verslag Afd. Natuurk. Konikl. Nederland, 20 (1912), 1354-1365; 21 (1912), 27-33. |
[21] |
A. M. Liapunov, Stability of Motion, Math. Sci. Engrg. 30 Academic Press, New York-London, 1966. xi+203 pp.doi: 10.1016/S0076-5392(08)61301-6. |
[22] |
-, Problème Général de la Stabilité du Mouvement, Annals of Mathematics Studies 17, Princeton University Press, Princeton, N. J.; Oxford University Press, London, 1947. iv+272 pp. |
[23] |
J. Llibre and R. Rabanal, Planar real polynomial differential systems of degree $n>3$ having a weak focus of high order, Rocky Mountain J. Math., 42 (2012), 657-693.doi: 10.1216/RMJ-2012-42-2-657. |
[24] |
L. Mazzi and M. Sabatini, Commutators and linearizations of isochronous centers, Atti Accad. Naz. Lincei Cl. Sci. Fis. Mat. Natur. Rend. Lincei (9) Mat. Appl., 11 (2000), 81-98. http://eudml.org/doc/252342 |
[25] |
J. M. Pearson, N. G. Lloyd and C. J. Christopher, Algorithmic derivation of centre conditions, SIAM Rev., 38 (1996), 619-636.doi: 10.1137/S0036144595283575. |
[26] |
H. Poincaré, Mémoire sur les courbes définies par une équation différentielle, Edit. Jacques Gabay, Paris, 1993. Reprinted from the original papers published in the Journal de Mathématiques, 7 (1881), 375-422, 8 (1882), 251-296, 1 (1885), 167-244, and 2 (1886), 151-217. |
[27] |
R. Roussarie, Bifurcations of Planar Vector Fields and Hilbert's Sixteenth Problem, Progress in Mathematics 164. Birkhäuser Verlag, Basel, 1998.doi: 10.1007/978-3-0348-8798-4. |
[28] |
S. D. Shafer, Symbolic computation and the cyclicity problem for singularities, J. Symbolic Comput., 47 (2012), 1140-1153.doi: 10.1016/j.jsc.2011.12.037. |
[29] |
E. P. Volokitin, Center conditions for a simple class of quintic systems. Int. J. Math. Math. Sci., 29 (2002), 625-632.doi: 10.1155/S0161171202012802. |
[30] |
-, Centering conditions for planar septic systems, Electron. J. Differential Equations, 34 (2003), 1-7. http://ejde.math.txstate.edu/Volumes/2003/34/abstr.html |