Open Access Open Access  Restricted Access Subscription or Fee Access

A Study of Systems of Nonlinear Delay Integral Equations by using the Method of upper and lower solutions

Abdellatif Sadrati, Abderrahim Zertiti


In this work, we use the method of upper and lower solutions to study the existence of positive and periodic solutions of nonlinear delay integral system which, from the biological point of view, models the evolution in time of two species with a periodic interaction. Our results are generalizations of some known results. An example is given to illustrate our results.


Nonlinear delay integral systems, positive periodic solutions.

Full Text:


Disclaimer/Regarding indexing issue:

We have provided the online access of all issues and papers to the indexing agencies (as given on journal web site). It’s depend on indexing agencies when, how and what manner they can index or not. Hence, we like to inform that on the basis of earlier indexing, we can’t predict the today or future indexing policy of third party (i.e. indexing agencies) as they have right to discontinue any journal at any time without prior information to the journal. So, please neither sends any question nor expects any answer from us on the behalf of third party i.e. indexing agencies.Hence, we will not issue any certificate or letter for indexing issue. Our role is just to provide the online access to them. So we do properly this and one can visit indexing agencies website to get the authentic information. Also: DOI is paid service which provided by a third party. We never mentioned that we go for this for our any journal. However, journal have no objection if author go directly for this paid DOI service.