A group theoretic characterization of Buekenhout–Metz unitals in [formula omitted] containing conics

Abstract

Let U be a unital in PG(2,q2), q=ph and let G be the group of projectivities of PG(2,q2) stabilizing U. In this paper we prove that U is a Buekenhout–Metz unital containing conics and q is odd if, and only if, there exists a point A of U such that the stabilizer of A in G contains an elementary Abelian p-group of order q2 with no non-identity elations.