Electronic Journal of Differential Equations,
Vol. 2007(2007), No. 137, pp. 1-9.

Title: On the solvability of a  fourth order operator
       differential equations

Author: Ahmed Nouar (Univ. de Skikda, Algeria)

Abstract: 
 We establish sufficient conditions for the solvability
 of a fourth order operator differential equation.
 These conditions are expressed in terms of operator coefficients.

Submitted February 24, 2007. Published October 17, 2007.
Math Subject Classifications: 47E05, 35K20.
Key Words: Operator Pencil; operator differential equation; 
           normal operator.