On the Branching of Solutions of Quadratic Differential Equations.
Per funzioni opportune si ottiene una formula di Parseval per operatori differenziali singolari di tipo dell'operatore radiale di Laplace-Beltrami. è una funzione spettrale generalizzata di tipo Marčenko e può essere rappresentata per mezzo di un certo nucleo della trasmutazione.
We study the dynamic behavior and stability of two connected Rayleigh beams that are subject to, in addition to two sensors and two actuators applied at the joint point, one of the actuators also specially distributed along the beams. We show that with the distributed control employed, there is a set of generalized eigenfunctions of the closed-loop system, which forms a Riesz basis with parenthesis for the state space. Then both the spectrum-determined growth condition and exponential stability...
This paper is devoted to the solvability of the Lyapunov equation A*U + UA = I, where A is a given nonselfadjoint differential operator of order 2m with nonlocal boundary conditions, A* is its adjoint, I is the identity operator and U is the selfadjoint operator to be found. We assume that the spectra of A* and -A are disjoint. Under this restriction we prove the existence and uniqueness of the solution of the Lyapunov equation in the class of bounded operators.
In this paper we define and study generalized Fourier transforms associated with some class of Schrodinger operators on . Next, we establish Paley-Wiener type theorems which characterize some functional spaces by their generalized Fourier transforms.