and Applied Analysis 3 2. Jost Solution of 1.4 We will denote the solution of 1.4 satisfying the condition lim x→∞ y x, λ e−iλx 1, λ ∈ C : {λ : λ ∈ C, Imλ ≥ 0}, 2.1 by e x, λ . The solution e x, λ is called the Jost solution of 1.4 . Under the condition ∫∞ 0 x ∣ ∣q x ∣ ∣dx < ∞, 2.2 the Jost solution has a representation

We consider a regular indefinite Sturm-Liouville problem with two self-adjoint boundary conditions, one being affinely dependent on the eigen-parameter. We give sufficient conditions under which a basis of each root subspace for this Sturm-Liouville problem can be selected so that the union of all these bases constitutes a Riesz basis of a corresponding weighted Hilbert space.

The dynamic analysis of structures using the nite element method leads to very large eigenvalue problems. Condensation is often required to reduce the number of degrees of freedom of these problems to manageable size. The (statically or dynamically) condensed problem can be considered as linearization of a matrix eigenvalue problem which is nonlinear with respect to the eigenparameter. As a con...

Sexual selection is responsible for much of the spectacular natural diversity of mating traits. It is unclear, however, how this powerful evolutionary force affects the evolution of traits unrelated to mating. Four recent theoretical studies have argued that sexual selection might increase the rate of adaptation, but each relies on the assumption of a substantial positive covariance between mal...