Comments on 'Design of Asymmetric Shift Operators for Efficient Decentralized Subspace Projection'

This correspondence disproves the main results in the paper "Design of Asymmetric Shift Operators for Efficient Decentralized Subspace Projection" by S. Mollaebrahim and B. Beferull-Lozano. Counterexamples and counterproofs are provided when applicable. A correction is suggested for some of the flaws. However, it does not seem possible to amend most of the flaws since the overall approach based on a Schur decomposition of the shift matrix does not appear to be helpful to solve the desired problem.