A NONOSCILLATION THEOREM FOR SECOND-ORDER NONLINEAR DIFFERENTIAL EQUATIONS WITH DECAYING COEFFICIENTS

2001 ◽  
Vol 33 (3) ◽  
pp. 299-308 ◽  
Author(s):  
JITSURO SUGIE

The purpose of this paper is to give sufficient conditions for all nontrivial solutions of the nonlinear differential equation x″ +a(t)g(x) = 0 to be nonoscillatory. Here, g(x) satisfies the sign condition xg(x) > 0 if x ≠ 0, but is not assumed to be monotone increasing. This differential equation includes the generalized Emden–Fowler equation as a special case. Our main result extends some nonoscillation theorems for the generalized Emden–Fowler equation. Proof is given by means of some Liapunov functions and phase-plane analysis.

Author(s):  
Jitsuro Sugie ◽  
Masakazu Onitsuka

The equation considered in this paper is tp(φp(x′))′ + g(x) = 0, where φp(x′) = |x′|p−2x′ with p > 1, and g(x) satisfies the signum condition xg(x) > 0 if x ≠ 0 but is not assumed to be monotone. Our main objective is to establish a criterion on g(x) for all non-trivial solutions to be non-oscillatory. The criterion is the best possible. The method used here is the phase-plane analysis of a system equivalent to this differential equation. The asymptotic behaviour is also examined in detail for eventually positive solutions of a certain half-linear differential equation.


2017 ◽  
Vol 19 (06) ◽  
pp. 1650057 ◽  
Author(s):  
Kōdai Fujimoto ◽  
Naoto Yamaoka

This paper deals with an equivalent system to the nonlinear differential equation of Liénard type [Formula: see text], where the range of the function [Formula: see text] is bounded. Sufficient conditions are obtained for the system to have at least one limit cycle. The proofs of our results are based on phase plane analysis of the system with the Poincaré–Bendixon theorem. Moreover, to show that these sufficient conditions are suitable in some sense, we also establish the results that the system has no limit cycles. Finally, some examples are given to illustrate our results.


2015 ◽  
Vol 58 (4) ◽  
pp. 723-729 ◽  
Author(s):  
Alfonso Castro ◽  
Emily M. Fischer

AbstractWe show that a class of semilinear Laplace–Beltrami equations on the unit sphere in ℝn has inûnitely many rotationally symmetric solutions. The solutions to these equations are the solutions to a two point boundary value problem for a singular ordinary differential equation. We prove the existence of such solutions using energy and phase plane analysis. We derive a Pohozaev-type identity in order to prove that the energy to an associated initial value problem tends to infinity as the energy at the singularity tends to infinity. The nonlinearity is allowed to grow as fast as |s|p-1s for |s| large with 1 < p < (n + 5)/(n − 3).


2021 ◽  
Vol 90 ◽  
pp. 203-204
Author(s):  
C. Rodrigues ◽  
M. Correia ◽  
J. Abrantes ◽  
B. Rodrigues ◽  
J. Nadal

2012 ◽  
Vol 2012 (04) ◽  
pp. P04004 ◽  
Author(s):  
Vandana Yadav ◽  
Rajesh Singh ◽  
Sutapa Mukherji

Sign in / Sign up

Export Citation Format

Share Document