# Tagged Questions

**6**

votes

**2**answers

237 views

### Are the reduced group Von Neumann algebra/ Group $C^{\ast}$ algebra functorial in the case of LCH groups

Let $G$ be a LCH group and $\mu$ be its left Haar measure. Call $\lambda_G : G \to U(L_2(G,\mu))$ the left regular representation. We can define the reduced $C^{\ast}$ algebra and reduced Von Neumann ...

**6**

votes

**2**answers

890 views

### The functoriality of group C* algebra structure

Hi!
Let G,H be discrete groups and f:G->H be any homomorphism of these groups. I have three questions about it:
1) how to prove the functoriality of the construction of universal C*-algebra of ...

**0**

votes

**0**answers

299 views

### Is there a good reference for studying the ideal structure of group C* algebras?

Is there a good reference for studying the ideal structure of group C* algebras?
Thanks.

**11**

votes

**3**answers

841 views

### The difference between $l^1(G)$ and the reduced group $C^*$ algebra $C_r^*(G)$

Let $G$ be a group and $l^2(G)$ the Hilbert space on $G$. The complex group algebra $CG$ can be imbedded in $B(l^2(G))$, the set of all bounded linear operators, by left translation. The reduced group ...

**13**

votes

**3**answers

1k views

### Is the group von Neumann algebra construction functorial?

Let $G$ be a group and $CG$ the complex group algebra over the field $C$ of complex number. The group von Neumann algebra $NG$ is the completion of $CG$ wrt weak operator norm in $B(l^2(G))$, the set ...