# From the strict Chebyshev approximant of a vector to the strict spectral approximant of a matrix

@article{Zietak2017FromTS, title={From the strict Chebyshev approximant of a vector to the strict spectral approximant of a matrix}, author={Krystyna Zietak}, journal={Banach Center Publications}, year={2017}, volume={112}, pages={307-346} }

The main aim of this review paper is approximation of a complex rectangular matrix, with respect to the unitarily invariant norms, by matrices from a linear subspace or from a convex closed subset of matrices. In particular, we focus on the properties and characterizations of the strict spectral approximant which is the best in some sense among all approximants to a given matrix with respect to the spectral norm. We formulate a conjecture that the strict spectral approximant to a matrix by…

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