The Weyl group of the fine grading of $sl(n,\mathbb{C})$ associated with tensor product of generalized Pauli matrices

Abstract

We consider the fine grading of $sl(n,\mb C)$ induced by tensor product of generalized Pauli matrices in the paper. Based on the classification of maximal diagonalizable subgroups of $PGL(n,\mb C)$ by Havlicek, Patera and Pelantova, we prove that any finite maximal diagonalizable subgroup $K$ of $PGL(n,\mb C)$ is a symplectic abelian group and its Weyl group, which describes the symmetry of the fine grading induced by the action of $K$, is just the isometry group of the symplectic abelian group $K$. For a finite symplectic abelian group, it is also proved that its isometry group is always generated by the transvections contained in it.