We show that almost every natural number M is the sum of four squares with all their prime factors smaller than exp(20(log M log log M) 1Â2 ).
On Groups that Differ in One of Four Squares
✍ Scribed by Aleš Drápal
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 371 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0195-6698
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✦ Synopsis
For a subgroup T of a group G(•), let L • (T ) and R • (T ) denote the sets of all left and right cosets, respectively. This paper is concerned with finite groups G(•) and G( * ), where the places in which the Cayley tables of the two groups differ is determined by subgroups
so that α 0 ⊆ α and β 0 ⊆ β, and so that x • y = x * y holds for (x, y) ∈ α × β if and only if (x, y) ∈ α 0 × β 0 . Given G(•) and G( * ), there can be multiple choices of S and H and it is proved in the paper that there always exists a choice for which S is a normal subgroup of both G(•) and G( * ), and G(•)/S = G( * )/S is either cyclic or dihedral (where the latter includes Klein's four-element group). The specification of S and H is precise enough to permit a detailed description of the set of products for which • and * differ and of the way in which they differ and, moreover, to permit the derivation of G( * ) from G(•) (without knowing G( * ) in advance).
📜 SIMILAR VOLUMES
A finite group G is said to have chain difference one if the lengths of any two unrefinable subgroup chains of G differ by at most one. Finite simple groups of Ž chain difference one were classified by B. Brewster et al. 1993, J. Algebra 160, . 179᎐191 using the classification of finite simple group
## Abstract In this paper, we study the problem of constructing sets of __s__ latin squares of order __m__ such that the average number of different ordered pairs obtained by superimposing two of the __s__ squares in the set is as large as possible. We solve this problem (for all __s__) when __m__