Let $T\neq\text{id}$$G$ be a positive invertiblel.c. group and $f$ belong to $C_c(G)$, the space of continuous functions with compact support. Define an operator$T_f$ on an infinite dimensional Hilbert space$L^2(G)$ by $T_f(g)=f*g$ (the convolution product). CanIf $\|T\|$$T_f$ is positive and invertible, could $\|T_f\|$ belong to the point spectrum of $T$$T_f$?