Published online by Cambridge University Press: 20 November 2018
In [8] Jha raised the following problem.
(*) Let Γ be a spread whose components are subspaces of V2n(GF(q)). Suppose G ≦ Aut Γ leaves a set of q + 1 components invariant while acting transitively on Γ\Δ.
Find the possibilities for Γ or, more generally, the possibilities for (G, Γ, n, q).
Many special cases of (*) have been settled. For instance, Cohen et al [1] have shown that if G fixes two non-zero points of V, that do not both lie in the same component of Γ, then Γ is the spread associated with either a Hall plane or the Lorimer-Rahilly plane of order 16 (LR-16) [14], [18].
Another such result is given in [8]; there it is shown that if q is a prime number and G is a one-dimensional projective unimodular group then Γ is the spread associated with one of the following translation planes:
(1) the Desarguesian planes of order 4, 8, or 9;
(2) the nearfield plane of order 9;
(3) LR-16;
(4) the translation plane JW-16, obtained by transposing the slope maps of LR-16 [19].