Let π be an affine plane of
order q2 that is coordinatized by a “derivable” semifield 𝒮 = (𝒮,+,⋅). If (𝒮,+) is a
right vector space over F = GF(q) then a plane π′ may be constructed from π using
Ostrom’s method of “derivation.”
The purpose of this article is to examine the planes π′ and their coordinate
structures (𝒮,+,∗). It is shown, in particular, that (𝒮,+,∗) is a (right) quasifield
which is neither a nearfield nor a semifield. Furthermore, it is shown that π′ is always
of Lenz-Barlotti class IVa. 1.
The automorphism groups of semifields of square order are also briefly
investigated.
|