Relative Difference Sets, Planar Functions, and Generalized Hadamard Matrices

On Generalized Hadamard Matrices and Difference Matrices: Z6

(Caution: please note Jennifer Seberry has tried but been unable to contact the persons named as co-authors. Apolgogies for half finished results.) We note that the literature on this subject is very disorganized. Authors have not read the literature on their own key-words and papers thus ignored, on the other hand papers have been claimed to be published which have not. We have put together th...

Difference sets and doubly transitive actions on Hadamard matrices

Non-affine groups acting doubly transitively on a Hadamard matrix have been classified by Ito. Implicit in this work is a list of Hadamard matrices with non-affine doubly transitive automorphism group. We give this list explicitly, in the process settling an old research problem of Ito and Leon. We then use our classification to show that the only cocyclic Hadamard matrices developed form a dif...

Jacket matrices constructed from Hadamard matrices and generalized Hadamard matrices

Semifields, Relative Difference Sets, and Bent Functions

Recently, the interest in semifields has increased due to the discovery of several new families and progress in the classification problem. Commutative semifields play an important role since they are equivalent to certain planar functions (in the case of odd characteristic) and to modified planar functions in even characteristic. Similarly, commutative semifields are equivalent to relative dif...

Two Generalized Constructions of Relative Difference Sets

We give two generalizations of some known constructions of relative difference sets. The first one is a generalization of a construction of RDS by Chen, Ray-Chaudhuri and Xiang using the Galois ring GR(4,m). The second one generalizes a construction of RDS by Ma and Schmidt from the setting of chain rings to a setting of more general rings.