Exact root degrees in the flat odd-prime-power extension #
theorem
MIPRE.LowDegree.BinaryPolynomial.flat_prime_power_minpoly
{F : Type u_1}
[Field F]
(f : Polynomial F)
(hf : f.Monic)
(hi : Irreducible f)
(q e : ℕ)
(hq : Nat.Prime q)
(hq2 : q ≠ 2)
(hn : ∀ (b : AdjoinRoot f), b ^ q ≠ AdjoinRoot.root f)
:
The flat extension root has the full specified minimal polynomial.
theorem
MIPRE.LowDegree.BinaryPolynomial.flat_prime_power_root_pow_minpoly
{F : Type u_1}
[Field F]
(f : Polynomial F)
(hf : f.Monic)
(hi : Irreducible f)
(q e : ℕ)
(hq : Nat.Prime q)
(hq2 : q ≠ 2)
(hn : ∀ (b : AdjoinRoot f), b ^ q ≠ AdjoinRoot.root f)
:
minpoly F (AdjoinRoot.root (f.comp (Polynomial.X ^ q ^ (e + 1))) ^ q) = f.comp (Polynomial.X ^ q ^ e)
Raising the flat extension generator to the base prime removes exactly one prime-power level from its minimal polynomial.