%0 Journal Article
%T The Pad¨¦ iterations for the matrix sign function and their reciprocals are optimal
%A Federico Greco
%A Bruno Iannazzo
%A Federico Poloni
%J Mathematics
%D 2010
%I arXiv
%R 10.1016/j.laa.2011.04.016
%X It is proved that among the rational iterations locally converging with order s>1 to the sign function, the Pad\'e iterations and their reciprocals are the unique rationals with the lowest sum of the degrees of numerator and denominator.
%U http://arxiv.org/abs/1011.1725v2