Far from a Point in the F4(q) Geometry

Abstract

We take the long-root geometry associated with the Chevalley group F4(q), q even, and consider the subgeometry induced on the set of points at maximal distance from a given point. We shall describe this geometry and in particular determine the parameters of a 12-class association scheme on its point set obtained by joining certain classes of a group scheme. © 2001 Academic Press.