Character Products and Q-Polynomial Group Association Schemes☆
Character Products and Q-Polynomial Group Association Schemes☆
复制标题
字符积与Q多项式群关联方案☆
DOI:
10.1006/jabr.1999.8205
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发表时间:
1998
影响因子:
0.9
通讯作者:
H. Suzuki
中科院分区:
文献类型:
--
作者:
Masao Kiyota;H. Suzuki
Abstract We study a finite group having a faithful character whose square has a small number of irreducible characters as constituents. Let Irr(G) be the set of absolutely irreducible ordinary characters of a finite group G. For each φ ∈ Irr(G), let φ = φ if φ is real valued and φ = φ + φ otherwise, where φ denotes the complex conjugate of φ. Let RIrr(G) = {φ | φ ∈ Irr(G)}. For χ ∈ RIrr(G), let χ 2 = b · 1 + a · χ + Ψ such that Ψ is a character of G which does not contain χ nor the principal character 1 as a constituent. We study the case when Ψ is a scalar multiple of a sum of the characters in IRrr(G), which are in a single orbit with respect to the action of the Galois group Gal(Q/Q(χ)). Here Q denotes the algebraic closure of Q in C and Q(χ) is the field generated by the values of χ. As an application, we give a classification of Q-polynomial group association schemes.