Abstract
In this paper, for interval parameter matrices, a method of estimating a domain of the eigenvalues on the complex plane is proposed. First, an interval parameter matrix is similarly transformed into a complex matrix whose elements lie on convex polygons on the complex plane. Second, by applying Gershgorin's theorem to this matrix, a sufficient condition for all the eigenvalues lie in a half-plane divided by a line on the complex plane is given. Then a scaling vector is introduced to this condition and an optimal scaling vector to obtain a sharper estimate is examined. By using this result for various gradients of the line, the domain of the eigenvalues can be estimated.
