Citation: | Xinjie Qian, Yang Shen, Jiazhong Yang. THE NUMBER OF RATIONAL SOLUTIONS OF ABEL EQUATIONS[J]. Journal of Applied Analysis & Computation, 2021, 11(5): 2535-2552. doi: 10.11948/20200475 |
In this paper, we study rational solutions of the Abel differential equations $ dy/dx = f_m(x)y^2+g_n(x)y^3 $, where $ f_m(x) $ and $ g_n(x) $ are real polynomials of degree $ m $ and $ n $ respectively. The main result of the paper is as follows: We give a systematic upper bound on the number of the nontrivial rational solutions of such equations in all these cases. Then we prove that these upper bounds can be reached in most cases. Finally, we present some examples of Abel equations having exactly $ i $ nontrivial rational solutions, where $ 1\leq i\leq 5 $.
[1] | D. M. Benardete, V. W. Noonburg and B. Pollina, Qualitative tools for studying periodic solutions and bifurcations as applied to the periodically harvested logistic equation, Amer. Math. Monthly, 2008, 115, 202-219. doi: 10.1080/00029890.2008.11920518 |
[2] | D. Behloul and S. Cheng, Computation of all polynomial solutions of a class of nonlinear differential equations, Computing, 2006, 77, 163-177. doi: 10.1007/s00607-005-0152-0 |
[3] | M. Briskin, J. P. Francoise and Y. Yomdin, Center conditions. Compositions of polynomials and moments on algebraic curves, Ergodic Theory Dynam. Systems, 1999, 19(5), 1201-1220. doi: 10.1017/S0143385799141737 |
[4] | M. Briskin, J. P. Francoise and Y. Yomdin, Center conditions. II. Parametric and model center problem, Israel J. Math., 2000, 118, 61-82. doi: 10.1007/BF02803516 |
[5] | B. Coll, A. Gasull and J. Llibre, Some theorems on the existence, uniqueness, and nonexistence of limit cycles for quadratic system, J. Diff. Eqns., 1987, 67(3), 372-399. doi: 10.1016/0022-0396(87)90133-1 |
[6] | A. Cima, A. Gasull and F. Maosas, On the number of polynomial solutions of Bernouilli and Abel polynomial differential equations, J. Diff. Eqns., 2017, 263, 7099-7122. doi: 10.1016/j.jde.2017.08.003 |
[7] | A. Gasull, J. Torregrosa and X. Zhang, The number of polynomial solutions of polynomial Riccati equations, J. Diff. Eqns., 2016, 261, 5071-5093. doi: 10.1016/j.jde.2016.07.019 |
[8] | A. Gasull and J. Llibre, Limit cycles for a class of Abel equations, SIAM J. Math. Anal., 1990, 21(5), 1235-1244. doi: 10.1137/0521068 |
[9] | J. Gin$\acute{e}$, M. Grau and J. Libre, On the polynomial limit cycles of polynomial differential equations, Israel J. Math., 2011, 181, 461-475. doi: 10.1007/s11856-011-0019-3 |
[10] | T. Harko and M. K. Mak, Relativistic dissipative cosmological models and Abel differential equation, Comput. Math. Appl., 2003, 46, 849-853. doi: 10.1016/S0898-1221(03)90147-7 |
[11] | C. Li, C. Liu, X. Wang and J. Wu, On the rational limit cycles of Abel equations, Chaos Solitons Fractals, 2018, 110, 28-32. doi: 10.1016/j.chaos.2018.03.004 |
[12] | J. Llibre and C. Valls, Polynomial solutions of equivariant polynomial Abel differential equations, Adv. Nonlinear Stud., 2018, 18, 537-542. doi: 10.1515/ans-2017-6043 |
[13] | E. D. Rainville, Necessary conditions for polynomial solutions of certain Riccati equations, Amer. Math. Monthly, 1936, 43, 473-476. doi: 10.1080/00029890.1936.11987882 |
[14] | C. Valls, Trigonometric polynomial solutions of equivariant trigonometric polynomial Abel differential equations, Electron. J. Diff. Eqns., 2017, 16, 261-270. |