Nonself-Adjoint Second-Order Difference Operators in Limit-Circle Cases

Homoclinic orbits for second order self-adjoint difference equations

In this paper we discuss how to use variational methods to study the existence of nontrivial homoclinic orbits of the following nonlinear difference equations Δ [ p(t)Δu(t − 1)]+ q(t)u(t)= f (t, u(t)), t ∈Z, without any periodicity assumptions on p(t), q(t) and f , providing that f (t, x) grows superlinearly both at origin and at infinity or is an odd function with respect to x ∈R, and satisfie...

Limit-point/limit-circle Results for Forced Second Order Differential Equations

In this paper, the authors consider both the forced and unforced versions of a second order nonlinear differential equation with a p-Laplacian. They give sufficient conditions as well as necessary and sufficient conditions for the unforced equation to be of the strong nonlinear limit-circle type, and they give sufficient conditions for the forced equation to be of the strong nonlinear limit-cir...

Limit Circle/Limit Point Criteria for Second-Order Sublinear Differential Equations with Damping Term

and Applied Analysis 3 2. Main Results To simplify notations, let α 1/2 k 1 and β 2k 1 /2 k 1 . We define

Limit Circle/Limit Point Criteria for Second-Order Superlinear Differential Equations with a Damping Term

Second order symmetry operators

Using systematic calculations in spinor language, we obtain simple descriptions of the second order symmetry operators for the conformal wave equation, the Dirac-Weyl equation and the Maxwell equation on a curved four dimensional Lorentzian manifold. The conditions for existence of symmetry operators for the different equations are seen to be related. Computer algebra tools have been developed ...