A note on 0-1 Schur multipliers Original Research Article

We answer a question of Q. Stout about the role of the triangular truncation in constructing 0-1 matrices that are not Schur multipliers. We also demonstrate that the triangular truncation on M2 has the third smallest norm (after 0 and 1) that any map induced by a 0-1 Schur multiplier can have.