Automorphisms and isomorphisms of Jha-Johnson semifields obtained from skew polynomial rings
We study the automorphisms of Jha-Johnson semifields obtained from an
invariant irreducible twisted polynomial f ∈ K[t; σ], where K =
Fq^n is a finite field and σ an automorphism of K of order n.
We compute all automorphisms and some automorphism groups when f ∈ K[t;
σ] has degree m and n ≥ m-1, in particular obtaining the automorphisms
of Sandler and Hughes-Kleinfeld semifields. Partial results are obtained for n
< m-1. We include the automorphisms of some Knuth semifields (which do not
arise from skew polynomial rings).
Isomorphism between Jha-Johnson semifields are considered as well.
C. Brown < Christian.brown@nottingham.ac.uk >
S. Pumpluen < Susanne.pumpluen@nottingham.ac.uk >
A. Steele < andrew.steele@aquaq.co.uk >