In this paper, we introduce the concept of upper and lower solutions for third order periodic boundary value problems. We show that the monotone iterative technique is valid and obtain the extremal solutions as limits of monotone sequences. We first present a new maximum principle for ordinary differential inequalities of third order that is interesting by itself.
Si da un risultato di esistenza di soluzioni periodiche per una equazione di Riccati in dimensione infinita.
This paper establishes effective sufficient conditions for existence and uniqueness of periodic solutions of a one-parameter differential equation vanishing at an arbitrary but fixed point.
By using the coincidence degree theory, we study a type of -Laplacian neutral Rayleigh functional differential equation with deviating argument to establish new results on the existence of -periodic solutions.
The paper is concerned with a stochastic delay predator-prey model under regime switching. Sufficient conditions for extinction and non-persistence in the mean of the system are established. The threshold between persistence and extinction is also obtained for each population. Some numerical simulations are introduced to support our main results.
Ce travail concerne le problème de Cauchy-Dirichlet pour des systèmes hyperboliques semilinéaires multidimensionnels perturbés par une “petite viscosité". Les solutions considérées sont et locales en temps, le but étant de décrire le comportement de la solution lorsque le paramètre de viscosité () tend vers zéro. Il s’agit d’un problème de perturbation singulière pour lequel une “couche limite" se forme au voisinage du bord. Par des méthodes inspirées de l’optique géométrique non linéaire, nous...
We establish new existence results for nontrivial solutions of some integral inclusions of Hammerstein type, that are perturbed with an affine functional. In order to use a theory of fixed point index for multivalued mappings, we work in a cone of continuous functions that are positive on a suitable subinterval of . We also discuss the optimality of some constants that occur in our theory. We improve, complement and extend previous results in the literature.