2 problems

Let $\Gamma$ be a discrete group, let $L(\Gamma)$ be its group von Neumann algebra, and let $\tau$ be the standard trace on $L(\Gamma)$. For $A\in M_n(\mathbb{Z}[\Gamma])$, write ……

Let $G$ be a countable i.c.c. group, meaning that every conjugacy class other than the identity class is infinite, and let $VN(G)$ be its group von Neumann algebra. Let $R$ be the…