Periodic points and chaotic-like dynamics of planar maps associated to nonlinear Hill's equations with indefinite weight.
We shall consider periodic problems for ordinary differential equations of the form where satisfies suitable assumptions. To study the above problem we shall follow an approach based on the topological degree theory. Roughly speaking, if on some ball of , the topological degree of, associated to (), multivalued Poincaré operator turns out to be different from zero, then problem () has solutions. Next by using the multivalued version of the classical Liapunov-Krasnoselskǐ guiding potential...
In this paper, we are concerned with a delayed multispecies competition predator-prey dynamic system with Beddington-DeAngelis functional response. Some sufficient conditions which guarantee the existence of a positive periodic solution for the system are obtained by applying the Mawhin coincidence theory. The interesting thing is that the result is related to the delays, which is different from the corresponding ones known from literature (the results are delay-independent).
We consider first order periodic differential inclusions in . The presence of a subdifferential term incorporates in our framework differential variational inequalities in . We establish the existence of extremal periodic solutions and we also obtain existence results for the “convex” and “nonconvex”problems.
By using the coincidence degree theory of Mawhin, we study the existence of periodic solutions for th order delay differential equations with damping terms . Some new results on the existence of periodic solutions of the investigated equation are obtained.
In this paper, we consider periodic solutions for a class of nonlinear evolution equations with non-instantaneous impulses on Banach spaces. By constructing a Poincaré operator, which is a composition of the maps and using the techniques of a priori estimate, we avoid assuming that periodic solution is bounded like in [1-4] and try to present new sufficient conditions on the existence of periodic mild solutions for such problems by utilizing semigroup theory and Leray-Schauder's fixed point theorem....
In this paper we prove the existence of periodic solutions for a class of nonlinear evolution inclusions defined in an evolution triple of spaces and driven by a demicontinuous pseudomonotone coercive operator and an upper semicontinuous multivalued perturbation defined on with values in . Our proof is based on a known result about the surjectivity of the sum of two operators of monotone type and on the fact that the property of pseudomonotonicity is lifted to the Nemitsky operator, which we...