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Centralisers of Galois group actions

Published online by Cambridge University Press:  17 April 2009

Mark Kisin
Affiliation:
Department of MathematicsUniversity of Sydney, Sydney NSW 2006Australia.
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Abstract

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If f is a polynomial over a field E, and σ a permutation of the roots of f, we show that σ is given by a polynomial p with coefficients in E (that is, p(a) = σ(a) for each root a of f) if and only if σ commutes with all the Galois automorphisms.

Type
Research Article
Copyright
Copyright © Australian Mathematical Society 1998

References

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