Periodicity in a logistic type system with several delays

Oscillation of a Logistic Difference Equation with Several Delays

Difference equations provide an important framework for analysis of dynamical phenomena in biology, ecology, economics, and so forth. For example, in population dynamics discrete systems adequately describe organisms for which births occur in regular, usually short, breeding seasons. Recently the problem of oscillation and nonoscillation of solutions for nonlinear delay difference equations has...

On Oscillation of a Generalized Logistic Equation with Several Delays

Periodicity in a System of Differential Equations with Finite Delay

The existence and uniqueness of a periodic solution of the system of differential equations d dt x(t) = A(t)x(t − ) are proved. In particular the Krasnoselskii’s fixed point theorem and the contraction mapping principle are used in the analysis. In addition, the notion of fundamental matrix solution coupled with Floquet theory is also employed.  

Pointwise almost periodicity in a generalized shift dynamical system

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Periodicity for a semi–ratio–dependent predator–prey system with delays on time scales

In this paper, the semi–ratio–dependent predator-prey system with nonmonotonic functional response on time scales is investigated. By using the coincidence degree theory, sufficient conditions for existence of periodic solutions are obtained. Keywords—Semi–ratio–dependent, predator–prey system, coincidence degree, time scales.