Quasioptimality of skeleton approximation of a matrix in the Chebyshev norm
S. A. Goreinov, E. E. Tyrtyshnikov · Doklady Mathematics · 2011
For a given matrix, considered is the rank- r skeleton approximation which uses r columns and r rows of the given matrix. It is demonstrated that if the minor residing on the intersection of the chosen columns and rows has the maximal modulus among all minors of order r , the considered approximation is quasioptimal in Chebyshev norm.