We use subfunctions and superfunctions to derive sufficient conditions for the existence of extremal solutions to initial value problems for ordinary differential equations with discontinuous and singular nonlinearities.

This paper deals with some existence results for a boundary value problem involving a nonlinear integrodifferential equation of fractional order with integral boundary conditions. Our results are based on contraction ...

Os sistemas de control suplementario da contaminación atmosférica, baseados en efectuar cambios nas condicións de operación para reduci-las emisións atmosféricas en condicións meteorolóxicas adversas, permiten evita-la ...

We prove that if there exists α ≤ β, a pair of lower and upper solutions of the first-order discrete periodic problem Δu(n) = f (n,u(n)); n ∈ IN ≡ {0, . . . ,N −1}, u(0) = u(N), with f a continuous N-periodic function ...

By employing the contraction mapping principle and applying Gronwall-Bellman's inequality, sufficient conditions are established to prove the existence and exponential stability of positive almost periodic solution for ...

Pulse vaccination, the repeated application of vaccine over a defined age range, is gaining prominence as an effective strategy for the elimination of infectious diseases. An SIR epidemic model with pulse vaccination and ...

We study the existence of solutions for a class of fractional differential equations. Due to the singularity of the possible solutions, we introduce a new and proper concept of periodic boundary value conditions. We present ...

We prove existence and uniqueness results in the presence of coupled lower and upper solutions for the general nth problem in time scales with linear dependence on the ith Δ- derivatives for i = 1, 2, . . . ,n, together ...

We study some existence results in a Banach space for a nonlocal boundary value problem involving a nonlinear differential equation of fractional order q given by cDqxt ft, xt , 0 <t< 1, q ∈ m − 1, m , m ∈ N, m ≥ 2, ...

A monotone iterative technique is applied to prove the existence of the extremal positive pseudosymmetric solutions for a three-point second-order p-Laplacian integrodifferential boundary value problem.