ABSTRACT

Let E denote the elation group of order q2 with axis x = 0 of the associated Desarguesian plane 1 . Note that

E =

* u;t =

2664 1 0 u+ 1t 1t 0 1 t u 0 0 1 0 0 0 0 1

3775 ;u; t 2 GF (q) + .

Let 2 and 3 denote two conical ‡ock spreads of odd order distinct from 1 in PG(3; q) that share precisely R0 with 1, which may be represented as:

i =

x = 0; y = x

u+ gi(t) fi(t)

t u

;u; t 2 GF (q)

;

i = 2; 3

and assume that for any given t0,

gi(t0) = 1t0;

fi(t0) = 1t0

implies t0 = 0 (this condition simply is that the given spreads share exactly R0 with 1): Note that either of these spreads could also be Desarguesian. Let E denote the subgroup of E that …xes R0 and hence is a collineation group of 1, and i, for i = 1; 2.