Stability of interval matrices: the real eigenvalue case

C.V. Hollot and A.C. Bartlett (1987) showed that testing at most 2 to the n/sup 2/ certain matrices for stability is sufficient for verifying stability of an n*n interval matrix with real eigenvalues. It is proven that this upper bound can be reduced to 2/sup 2n-1/, and a special case where testing only two matrices is needed is considered.<
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