Existence and Multiplicity Results for Periodic Solutions of Semilinear Duffing Equations

Boundedness of solutions for semilinear duffing equations

Exact Multiplicity for Periodic Solutions of Duffing type

In this paper, we study the following Duffing-type equation: x′′ + cx′ + g(t, x) = h(t), where g(t, x) is a 2π-periodic continuous function in t and concave-convex in x, and h(t) is a small continuous 2π-periodic function. The exact multiplicity and stability of periodic solutions are obtained.

Existence and multiplicity of positive solutions for a coupled system of perturbed nonlinear fractional differential equations

In this paper, we consider a coupled system of nonlinear fractional differential equations (FDEs), such that both equations have a particular perturbed terms. Using emph{Leray-Schauder} fixed point theorem, we investigate the existence and multiplicity of positive solutions for this system.

Existence and multiplicity of periodic solutions and subharmonic solutions for a class of elliptic equations

This paper focuses on the following elliptic equation { − u ′′ − p(x)u = f(x,u), a.e. x ∈ [0, l], u(0) − u(l) = u ′(0) − u ′(l) = 0, where the primitive function of f(x,u) is either superquadratic or asymptotically quadratic as |u| → ∞, or subquadratic as |u| → 0. By using variational method, e.g. the local linking theorem, fountain theorem, and the generalized mountain pass theorem, we establi...

Existence and multiplicity of positive solutions for a class of semilinear elliptic system with nonlinear boundary conditions

This study concerns the existence and multiplicity of positive weak solutions for a class of semilinear elliptic systems with nonlinear boundary conditions. Our results is depending on the local minimization method on the Nehari manifold and some variational techniques. Also, by using Mountain Pass Lemma, we establish the existence of at least one solution with positive energy.