Spectral mapping theorem of an abstract quantum walk

Yusuke Higuchi, Etsuo Segawa, Akito Suzuki

Given two Hilbert spaces, $\mathcal{H}$ and $\mathcal{K}$, we introduce an abstract unitary operator $U$ on $\mathcal{H}$ and its discriminant $T$ on $\mathcal{K}$ induced by a coi…