In this paper, we "rst determine the exact values of s(2, t), a function de"ned by X.-D. Hou [preprint], which depends on the structure of GR(4, t). This result gives the exact range of parameters of the partial di!erence sets in 9R constructed by Chen et al. (J. Combin. ΒΉheory Ser. A 76 (1996), 179
Constructions of Partial Difference Sets and Relative Difference Sets Using Galois Rings II
β Scribed by Yu Qing Chen; D.K. Ray-Chaudhuri; Qing Xiang
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 745 KB
- Volume
- 76
- Category
- Article
- ISSN
- 0097-3165
No coin nor oath required. For personal study only.
β¦ Synopsis
In a previous paper, [Des., Codes and Cryptogr. 8 (1996), 215 227]; we used Galois rings to construct partial difference sets, relative difference sets and a difference set. In the present paper, we first generalize and improve the construction of partial difference sets in [Des., Codes and Cryptogr. 8 (1996), 215 227]; also we obtain a family of relative difference sets from these partial difference sets. Second, we construct a class of relative difference sets in (Z 4 ) 2m+1 Γ (Z 4 ) r Γ (Z 2 Γ Z 2 ) s , r+s=m, r, s 0 with respect to a subgroup (Z 2 ) 2m+1 . These constructions make use of character sums from Galois rings, and relate relative difference sets to Hadamard difference sets.
1996 Academic Press, Inc.
1. Introduction
Let G be a finite group of order
represent each nonidentity element in D exactly * times and each nonidentity element not contained in D exactly + times. D is called abelian if G is abelian. It is well known that a PDS D with e Γ D and [d &1 : d # D]=D is equivalent to a strongly regular Cayley graph, such a PDS is called regular. The study of partial difference sets is closely related to partial geometries, Schur rings, strongly regular Cayley graphs and two-weight codes. The recent survey of Ma [5] contains very detailed descriptions of these connections.
Assume that v=mn and that G contains a normal subgroup N of order n.
d 1 {d 2 , represent each element in G "N exactly * times and each nonidentity element in N zero time. If G=H_N, where H is article no. 0100
π SIMILAR VOLUMES
gave two new constructions for semi-regular relative di!erence sets (RDSs). They asked if the two constructions could be uni"ed. In this paper, we show that the two constructions are closely related. In fact, the second construction should be viewed as an extension of the "rst. Furthermore, we gener
We generalize a construction of partial di!erence sets (PDS) by Chen, Ray-Chaudhuri, and Xiang through a study of the TeichmuK ller sets of the Galois rings. Let R"GR(p, t) be the Galois ring of characteristic p and rank t with TeichmuK ller set ΒΉ and let : RPR/pR be the natural homomorphism. We giv
## Abstract A partial difference set (PDS) having parameters (__n__^2^, __r__(__n__β1), __n__+__r__^2^β3__r, r__^2^β__r__) is called a __Latin square type__ PDS, while a PDS having parameters (__n__^2^, __r__(__n__+1), β__n__+__r__^2^+3__r, r__^2^ +__r__) is called a __negative Latin square type__
Building sets are a successful tool for constructing semi-regular divisible difference sets and, in particular, semi-regular relative difference sets. In this paper, we present an extension theorem for building sets under simple conditions. Some of the semi-regular relative difference sets obtained
In this paper, a new family of relative difference sets with parameters Γ°m; n; k; lΓ ΒΌ ððq 7 Γ 1Γ=Γ°q Γ 1Γ; 4Γ°q Γ 1Γ; q 6 ; q 5 =4Γ is constructed where q is a 2-power. The construction is based on the technique used in [2]. By a similar method, we also construct some new circulant weighing matrices