A note on reduced and von Neumann algebraic free wreath products

Abstract

In this paper, we study operator algebraic properties of the reduced and von Neumann algebraic versions of the free wreath products $\mathbb{G}{\wr }_{\ast }{S}_N^{+}$, where $\mathbb{G}$ is a compact matrix quantum group. Based on recent result on their corepresentation theory by Lemeux and Tarrago, we prove that $\mathbb{G}{\wr }_{\ast }{S}_N^{+}$ is of Kac type whenever $\mathbb{G}$ is, and that the reduced version of $\mathbb{G}{\wr }_{\ast }{S}_N^{+}$ is simple with unique trace state whenever $N\ge 8$. Moreover, we prove that the reduced von Neumann algebra of $\mathbb{G}{\wr }_{\ast }{S}_N^{+}$ does not have property $\Gamma$.

arXiv comment14 pages