Resumen de Spectral properties of a non selfadjoint system of differential equations with a spectral parameter in the boundary condition
Esra Kir Arpat, Gülen Bascanbaz Tunca, Canan Yanik
In this paper we investigated the spectrum of the operator L(λ) generated in Hilbert Space of vector-valued functions L2 (R+, C2) by the system iy0 1 + q1 (x) y2 = λy1, −iy0 2 + q2 (x) y1 = λy2 (0.1) , x ∈R+ := [0,∞), and the spectral parameter- dependent boundary condition (a1λ + b1) y2 (0, λ) − (a2λ + b2) y1 (0, λ)=0, where λ is a complex parameter, qi, i = 1, 2 are complex-valued functions ai 6= 0, bi 6= 0, i = 1, 2 are complex constants. Under the condition sup x∈R+ {exp εx |qi (x)|} < ∞, i = 1, 2,ε> 0, we proved that L(λ) has a finite number of eigenvalues and spectral singularities with finite multiplicities. Furthermore we show that the principal functions corresponding to eigenvalues of L(λ) belong to the space L2 (R+, {C2) and the principal functions corresponding to spectral singularities belong to a Hilbert space containing L2 (R+, C2).
