SOME OPERATORS ACTING ON WEIGHTED SEQUENCE SPACES AND APPLICATIONS

Author

Departamento de Matematica y Ciencia de la Computacion, Facultad de Ciencias, Universidad de Santiago de Chile, Casilla 307-Correo2, Santiago, Chile

Abstract

This paper considers the problem of constructing an evolution family for

the linear non autonomous Cauchy problem

()

@

@t

u(t) ???? A(t)u(t) = 0; u(????1) = x 2 RN;

where A 2 C([????1; 1];RNN): The essence of the method is that the evolution family is

sought in the form of a series of Chebyshev polynomials. Then, by de ning appropriate

weighted sequence spaces and matrices of linear operators, we are able to obtain a suf-

cient condition - based only in the given data - for the representation of the solution

of the initial value problem (). The method is motivated for practical considerations in

the context of Magnetic Resonance Imaging.

Keywords