Generic Polynomials with Few Parameters
Generic Polynomials with Few Parameters
复制标题
参数很少的泛型多项式
DOI:
10.1006/jsco.1999.0385
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发表时间:
2000
期刊:
影响因子:
--
通讯作者:
Elena Mattig
中科院分区:
文献类型:
--
作者:
G. Kemper;Elena Mattig
We call a polynomial g(t1, . . . , tm,X ) over a field K generic for a group G if it has Galois group G as a polynomial inX , and if every Galois field extension N/L withK?L and Gal(N/L) ?G arises as the splitting field of a suitable specializationg (?1, . . . , ?m, X) with?i?L. We discuss how the rationality of the invariant field of a faithful linear representation leads to a generic polynomial which is often particularly simple and therefore useful. Then we consider various examples and applications in characteristic 0 and in positive characteristic. These include results on so-called vectorial polynomials and a generalization of an embedding criterion given by Abhyankar. We give recursive formulas for generic polynomials over a field of defining characteristic for the groups of upper unipotent and upper triangular matrices, and explicit formulae for generic polynomials for the groups GU2(q2) andGO3 (q).