Overlap between switching methods from different orthogonal matrices
Prove or disprove that distinct indecomposable orthogonal matrices $Q_1$ and $Q_2$ of the same size cannot induce switching methods with the same $Q$-respecting vectors up to a permutation that also maps the associated switching graphs $\Gamma_1$ and $\Gamma_2$ to one another.
References
The authors are not aware of any such pair of matrices, but could not prove these do not exist.
— Counting cospectral graphs obtained via switching
(2503.08627 - Abiad et al., 11 Mar 2025) in Section 3.1, subsection “Adding bounds for different switching methods”