Absztrakt: | We study the asymptotic behavior of the solutions of a broad
class of second order nonlinear differential equations, namely,
$$ (E)\quad (a(t)x')'+h(t,x,x')+q(t)f(x)=e(t,x,x'). $$ Equation
(E) can be interpreted as the equation of the motion of a mechanical
system with one degree of freedom having kinetic energy $a(t)[x']\sp
2/2$ and potential energy q(t)$\int\sp{x}\sb{0}f(u)du$. The system
is under the action of non-potential forces $h(t,x,x')$ and $e(t,x,x')$.
The force h may typically be damping while e denotes a perturbation. |