How to check if permutation induces an element of the Galois group.












1












$begingroup$


Let $f in mathbb Q[X]$ be irreducible of degree $n$ with zeros $alpha_1,dots,alpha_n in mathbb C$. Further, let $L$ be the splitting field of $f$ and $sigma in S_n$.



Is there an easy way to check if $ alpha_i mapsto alpha_{sigma(i)} $ induces an automorphism of $L$?










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$endgroup$












  • $begingroup$
    Voted to close as too broad... no, there isn't an easy way to check it.
    $endgroup$
    – Kenny Lau
    Dec 31 '18 at 22:41
















1












$begingroup$


Let $f in mathbb Q[X]$ be irreducible of degree $n$ with zeros $alpha_1,dots,alpha_n in mathbb C$. Further, let $L$ be the splitting field of $f$ and $sigma in S_n$.



Is there an easy way to check if $ alpha_i mapsto alpha_{sigma(i)} $ induces an automorphism of $L$?










share|cite|improve this question









$endgroup$












  • $begingroup$
    Voted to close as too broad... no, there isn't an easy way to check it.
    $endgroup$
    – Kenny Lau
    Dec 31 '18 at 22:41














1












1








1





$begingroup$


Let $f in mathbb Q[X]$ be irreducible of degree $n$ with zeros $alpha_1,dots,alpha_n in mathbb C$. Further, let $L$ be the splitting field of $f$ and $sigma in S_n$.



Is there an easy way to check if $ alpha_i mapsto alpha_{sigma(i)} $ induces an automorphism of $L$?










share|cite|improve this question









$endgroup$




Let $f in mathbb Q[X]$ be irreducible of degree $n$ with zeros $alpha_1,dots,alpha_n in mathbb C$. Further, let $L$ be the splitting field of $f$ and $sigma in S_n$.



Is there an easy way to check if $ alpha_i mapsto alpha_{sigma(i)} $ induces an automorphism of $L$?







number-theory permutations galois-theory symmetric-groups






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Dec 11 '18 at 15:57









principal-ideal-domainprincipal-ideal-domain

2,756522




2,756522












  • $begingroup$
    Voted to close as too broad... no, there isn't an easy way to check it.
    $endgroup$
    – Kenny Lau
    Dec 31 '18 at 22:41


















  • $begingroup$
    Voted to close as too broad... no, there isn't an easy way to check it.
    $endgroup$
    – Kenny Lau
    Dec 31 '18 at 22:41
















$begingroup$
Voted to close as too broad... no, there isn't an easy way to check it.
$endgroup$
– Kenny Lau
Dec 31 '18 at 22:41




$begingroup$
Voted to close as too broad... no, there isn't an easy way to check it.
$endgroup$
– Kenny Lau
Dec 31 '18 at 22:41










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