Projective planes and dihedral groups Original Research Article

In the present article we shall show that any two disjoint Baer subplanes of PG(2, q2) are contained in exactly one Singer-Baer partition. Given two disjoint Baer subplanes of P = PG(2, q2) with Baer involutions τ0 and τ1 we shall see that δ := τ0τ1 is a projective collineation whose order is a divisor of q2 − q + 1. If o(δ) = q2 − q + 1, then the point orbits of P under the action of 〈δ〉 are so-called Kestenband arcs.