A new infinite family of covers of complete graphs that admit a half-transitive action of a Suzuki simple group

Source abstract

We construct a new infinite family of antipodal $2(q-1)$-covers of complete graphs $K_{q^2+1}$ of diameter $3$, where $q=2^{2e+1}\ge 8$, admitting a half-transitive action of the Suzuki simple group $Sz(q)$. We further show that each constructed cover admits an involutory automorphism interchanging the two $Sz(q)$-orbits on arcs, which yields that its full automorphism group is arc-transitive.