Stability robustness of generalized eigenvalues

The stability robustness of the generalized eigenvalues of matrix pairs with real perturbations is considered. The problem is estimate the norm of the smallest destabilizing perturbation on a stable matrix pair. Sufficient conditions on the norm of the perturbations are given which guarantee the stability of the perturbed matrix pair. The results obtained can be applied to the stability robustness analysis of singularly perturbed systems and descriptor systems and to a new kind of problem called the minimum phase robustness problem