On oscillatory properties of an -th-order system of linear differential equations with deviating arguments.
The paper deals with the oscillation of a differential equation as well as with the structure of its fundamental system of solutions.
A necessary and sufficient condition is given for the carrying simplex of a dissipative totally competitive system of three ordinary differential equations to have a peak singularity at an axial equilibrium. For systems of Lotka-Volterra type that result translates into a simple condition on the coefficients.
In this paper, by using the topological degree theory for multivalued maps and the method of guiding functions in Hilbert spaces we deal with the existence of periodic oscillations for a class of feedback control systems in Hilbert spaces.
The purpose of this paper is to study the existence of periodic solutions for the non-autonomous second order Hamiltonian system Some new existence theorems are obtained by the least action principle.