An upper bound for an exceptional automorphism group

Xu Zhuang

Let $q=p^h>7$ be odd, put $m=(q+1)/2$, and suppose that $i=(m-2)/2$ satisfies $\gcd (i,m)=\gcd (i+2,m)=1$. For the ${\mathbf{F}}_{q^2}$-maximal function field $\mathcal{F}_i=\mathbf{F}…