Systems of reproducing kernels and their biorthogonal: completeness or incompleteness?

Anton Baranov, Yurii Belov

Let $\{v_n\}$ be a complete minimal system in a Hilbert space $\mathcal{H}$ and let $\{w_m\}$ be its biorthogonal system. It is well known that $\{w_m\}$ is not necessarily complet…