Spectral radius interpolation and robust control

In a previous paper (1987) Tannenbaum discussed an interpolation problem closely related to the multivariate gain margins of J.C. Doyle (1984) and M.G. Safonov (1980). For this interpolation problem, it is necessary to interpolate on the disk with analytic matrices of bounded spectral radius instead of norm (as in classical H/sup infinity / theory). The mathematical solution to this problem is presented.<
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