Galois group
Noun
Meaning
Galois group (plural Galois groups)
(algebra, Galois theory) The automorphism group of a Galois extension.
Examples
Specifically, the Galois group of F over E, denoted Gal(F/E), is the group of field automorphisms of F that are trivial on E (i.
The Galois group of every finite extension of a finite field is finite and cyclic, with an iterate of the Frobenius endomorphism as its generator.
Since the Galois group of the general quintic equation is isomorphic to the symmetric group on five letters, and this normal subgroup is simple and non-abelian, the general quintic equation does not have a solution in radicals.
Every polynomial equation in one variable has a Galois group, that is a certain permutation group on its roots.
He realized that the algebraic solution to a polynomial equation is related to the structure of a group of permutations associated with the roots of the polynomial, the Galois group of the polynomial.
In this case, the group that exchanges the two roots is the Galois group belonging to the equation.