Quantum unitary group $U_{q,\Theta}(3)$ for complex deformation parameters

Abstract

In this article, we consider a particular Hayashi $R$-matrix that satisfies the Yang-Baxter equation $R_{12}R_{13}R_{23}=R_{23}R_{13}R_{12}$. Using the FRT-bialgebra technique and Woronowicz's method of construction, we construct a concrete compact quantum group $U_{q,\Theta}(3)$ for non zero real $q$ and modulus one complex deformation parameters $\theta_{ij}$. We then study in detail the irreducible $*$-representations of the underlying $C^*$-algebra $C(U_{q,\Theta}(3))$, using the representations of the three dimensional noncommutative torus. Also, a monomial basis for the dense Hopf *-algebra $\mathbb{C}[U_{q,\Theta}(3)]$ is obtained.