Intertwining of $*$-regular $q$-isometric dilations

Abstract

A tuple $\underline{T}=(T_1,\dots,T_k)$ of contractions on a Hilbert space $\mathcal H$ is said to be $q$-commuting with $\|q\|=1$ if there exists a family of scalars $q=\{q_{ij}\in\mathbb C : |q_{ij}|=1,\ q_{ij}=q_{ji}^{-1},\ 1\le i<j\le k\}$ such that $T_iT_j=q_{ij}T_jT_i$ for $1\le i<j\le k$. In this article, we characterize $q$-commuting pairs of contractions with $\|q\|=1$ that admit a minimal $*$-regular $q$-isometric dilation. We present sufficient conditions for the commutant lifting theorem for such pairs. Moreover, sufficient conditions are obtained for a $q$-commuting triple of contractions with $\|q\|=1$ to admit a $q$-isometric dilation.