On exponentiality of automorphisms of ${\mathbf{A}}^n$ of order $p$ in characteristic $p>0$

Shigeru Kuroda

Let $X$ be an integral affine scheme of characteristic $p>0$, and $\ddot{I}ƒ$ a non-identity automorphism of $X$. If $\ddot{I}ƒ$ is $\text{exponential}$, i.e., induced from a ${\mathbf{G}}_a$-actio…