A noncommutative construction of families of biunitary matrices and application to subfactors

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Bakshi, Keshab Chandra, Guin, Satyajit, Guruprasad
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866912824265015296
author Bakshi, Keshab Chandra
Guin, Satyajit
Guruprasad
author_facet Bakshi, Keshab Chandra
Guin, Satyajit
Guruprasad
contents We introduce a construction that, given a pair (u,v) of complex Hadamard matrices of the same order, generates infinitely many biunitary matrices of varying (and distinct) orders. As a key application, this framework yields nested sequences of vertex model subfactors that are not a tower of downward basic construction. Notably, the construction is noncommutative: interchanging the matrices (i.e., considering (v,u) instead of (u,v)) can lead to non-isomorphic subfactors. Focusing on the Hadamard equivalence class of the Fourier matrix, we provide a full characterization of the resulting vertex model subfactors, along with explicit computations of their relative commutants. Along the way, we conduct a detailed study of certain naturally arising inner and outer automorphisms that play a key role in the structure of these subfactors.
format Preprint
id arxiv_https___arxiv_org_abs_2506_14351
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A noncommutative construction of families of biunitary matrices and application to subfactors
Bakshi, Keshab Chandra
Guin, Satyajit
Guruprasad
Operator Algebras
Functional Analysis
46L37, 46L55
We introduce a construction that, given a pair (u,v) of complex Hadamard matrices of the same order, generates infinitely many biunitary matrices of varying (and distinct) orders. As a key application, this framework yields nested sequences of vertex model subfactors that are not a tower of downward basic construction. Notably, the construction is noncommutative: interchanging the matrices (i.e., considering (v,u) instead of (u,v)) can lead to non-isomorphic subfactors. Focusing on the Hadamard equivalence class of the Fourier matrix, we provide a full characterization of the resulting vertex model subfactors, along with explicit computations of their relative commutants. Along the way, we conduct a detailed study of certain naturally arising inner and outer automorphisms that play a key role in the structure of these subfactors.
title A noncommutative construction of families of biunitary matrices and application to subfactors
topic Operator Algebras
Functional Analysis
46L37, 46L55
url https://arxiv.org/abs/2506.14351