The stability of a delay differential equation can be investigated on the basis of the root location of the characteristic function. Though a number of stability criteria are available, they usually do not provide any information about the characteristic root with maximal real part, which is useful in justifying the stability and in understanding the system performances. Because the characteris...

where X ∈ M(n,m)(K), play a central role in many areas of applied mathematics and in particular in systems and control theory. It is well known that if K is an algebraically closed field then the matrix equation (1) possesses a unique solution if and only if the matrices A and B have no common eigenvalues (see [[3]] and [11]). In this work we give a brief survey of methods used to solve the (SM...