The association scheme having the same intersection numbers as those of the group association scheme X(PSL(2, 7)) is shown to be isomorphic to X(PSL(2, 7)), where PSL(2, 7) is the 2-dimensional projective special linear group over the field of order 7.
Characterization of the Group Association Scheme of the Symmetric Group
β Scribed by M. Tomiyama; N. Yamazaki
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 363 KB
- Volume
- 19
- Category
- Article
- ISSN
- 0195-6698
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β¦ Synopsis
Let n be a non-zero positive integer and (n) the set of all partitions of n. There is a oneto-one correspondence between (n) and the set of the conjugacy classes of S n , the symmetric group of degree n. Let X (S n ) = (S n , {R * Ξ» } Ξ»β (n) ) be the group association scheme of S n and X = (X, {R Ξ» } Ξ»β (n) ) be an association scheme having intersection numbers identical to those of X (S n ). Suppose there exists no set of four vertices
. Then X is shown to be isomorphic to X (S n ). (In [17], the authors show that if n β₯ 5, X does not possess four vertices of this type.)
π SIMILAR VOLUMES
Let S n be a double cover of the finite symmetric group S n of degree n, i.e., S n has a central involution z such that S n Γ(z) & S n . An irreducible character of S n is called ordinary or spin according to whether it has z in its kernel or not. The purpose of this paper is to determine the distr
3uppose A and x are different irreduc\*ible characters of the symmetric group S,. If the jyartition of WI to which A corresponds majorizes the partition to which x corresponds, then .4 (7)/h(e) > x(7)/x(e)+ where T is a transpxition and e is the identity.