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Keywords:
quasi-linear second order equations; unbounded; oscillatory and non-oscillatory solutions; fixed-point techniques
Summary:
The paper deals with the quasi-linear ordinary differential equation $(r(t)\varphi (u^{\prime }))^{\prime }+g(t,u)=0$ with $t \in [0, \infty )$. We treat the case when $g$ is not necessarily monotone in its second argument and assume usual conditions on $r(t)$ and $\varphi (u)$. We find necessary and sufficient conditions for the existence of unbounded non-oscillatory solutions. By means of a fixed point technique we investigate their growth, proving the coexistence of solutions with different asymptotic behaviors. The results generalize previous ones due to Elbert–Kusano, [Acta Math. Hung. 1990]. In some special cases we are able to show the exact asymptotic growth of these solutions. We apply previous analysis for studying the non-oscillatory problem associated to the equation when $\varphi (u)=u$. Several examples are included.
References:
[1] Cecchi M., Marini M., Villari G.: On some classes of continuable solutions of a nonlinear differential equation. J. Diff. Equat. 118 (1995), 403–419. Zbl 0827.34020
[2] Cecchi M., Marini M., Villari G.: Topological and variational approaches for nonlinear oscillation: an extension of a Bhatia result. Proc. First World Congress Nonlinear Analysts, Walter de Gruyter, Berlin, 1996, 1505–1514. Zbl 0846.34027
[3] Cecchi M., Marini M., Villari G.: Comparison results for oscillation of nonlinear differential equations. Nonlin. Diff. Equat. Appl. 6 (1999), 173–190. Zbl 0927.34023
[4] Coffman C. V., Wong J. S. W.: Oscillation and nonoscillation of solutions of generalized Emden–Fowler equations. Trans. Amer. Math. Soc. 167 (1972), 399–434. Zbl 0278.34026
[5] Došlá Z., Vrkoč I.: On an extension of the Fubini theorem and its applications in ODEs. Nonlinear Anal. 57 (2004), 531–548. Zbl 1053.34033
[6] Elbert A., Kusano T.: Oscillation and non-oscillation theorems for a class of second order quasilinear differential equations. Acta Math. Hung. 56 (1990), 325–336. MR 1111319
[7] Kiyomura J., Kusano T., Naito M.: Positive solutions of second order quasilinear ordinary differential equations with general nonlinearities. St. Sc. Math. Hung. 35 (1999), 39–51. MR 1690272
[8] Kusano T., Norio Y.: Nonoscillation theorems for a class of quasilinear differential equations of second order. J. Math. An. Appl. 189 (1995), 115–127. MR 1312033 | Zbl 0823.34039
[9] Tanigawa T.: Existence and asymptotic behaviour of positive solutions of second order quasilinear differential equations. Adv. Math. Sc. Appl. 9, 2 (1999), 907–938. MR 1725693
[10] Wang J.: On second order quasilinear oscillations. Funk. Ekv. 41 (1998), 25–54. MR 1627369 | Zbl 1140.34356
[11] Wong J. S. W.: On the generalized Emden–Fowler equation. SIAM Review 17 (1975), 339–360. MR 0367368 | Zbl 0295.34026
[12] Wong J. S. W.: A nonoscillation theorem for Emden–Fowler equations. J. Math. Anal. Appl. 274 (2002), 746–754. MR 1936728 | Zbl 1036.34039
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