A fast algorithm for the computation of the optimally frequency-dependent scaled H-infinity-norm of a finite-dimensional LTI system is presented. It is well known that this quantity is an upper bound to the "mu-norm"; furthermore, it was recently shown to play a special role in the context of slowly time-varying uncertainty. Numerical experimentation suggests that the algorithm generally converges quadratically. (C) 2000 Elsevier Science Ltd. All rights reserved.
Lawrence, C., Tits, A., & Van Dooren, P. (2000). A fast algorithm for the computation of an upper bound on the mu-norm. Automatica, 36(3), 449-456. https://doi.org/10.1016/S0005-1098(99)00165-X (Original work published 2000)