ScalingStacks

We define an endomorphism $\tau$ of $m^{\prime\prime}$ by

(4.3.3)

$$\tau=\left(\begin{matrix}\tau_{2}&0&0&0\\ 0&0&\sigma^{-1}&0\\ 0&0&0&0\\ 0&0&0&\tau_{1}\end{matrix}\right).$$