For a rational matrix function Φ with poles outside the unit circle, we estimate the degree of the unique superoptimal approximation 𝒜Φ by matrix functions analytic in the unit disk. We obtain sharp ...

This report presents near-minimax rational approximations for the Bickley functions $Ki_1(x)$ for $x \geqslant 0, Ki_2(x)$ and $Ki_3(x)$ for $0 \leqslant x \leqslant ...