Association schemes from the action of $PGL(2,q)$ fixing a nonsingular conic in PG(2,q)

Henk D. L. Hollmann, Qing Xiang

The group $PGL(2,q)$ has an embedding into $PGL(3,q)$ such that it acts as the group fixing a nonsingular conic in $PG(2,q)$. This action affords a coherent configuration $R(q)$ on…