Conjugate pairs of Hadamard subfactors and vertex models
摘要
We show that any two Hadamard subfactors arising from a pair of distinct complex Hadamard matrices of order 3 are either equal or conjugate by a unitary in the relative commutant of their intersection. Moreover, when the Hadamard subfactors are not equal, we prove the factoriality of their intersection, and it turns out to be a vertex model subfactor. We compute the first relative commutant and characterize this subfactor by identifying it with a particular type of Krishnan–Sunder subfactor. A few key invariants, including the Pimsner–Popa probabilistic number, the angle, and the Connes–Størmer relative entropy for the pair of Hadamard subfactors are computed to understand their relative position.