Module

RootFiberTransitivity.lean

Nyll.EtaleFundamentalGroups.Kummer.AdjoinRoot.RootFiberTransitivity
1 declaration indexed from sourceView source ↗

Unique root scaling over a separably closed field

Two nonzero roots of the same invertible power over an extension field differ by exactly one root of unity in the separably closed base field.

Declarations

EtaleFundamentalGroups.Kummer.existsUnique_rootScale

Two nonzero roots of the same prime-to-characteristic power differ by a unique root of unity in the separably closed base field.

Source context 3 commands

Surrounding namespaces, section variables, and local commands at this declaration.

noncomputable section
universe u v
namespace EtaleFundamentalGroups.Kummer
theorem existsUnique_rootScale {K : Type u} [Field K] [IsSepClosed K]
    {Ω : Type v} [Field Ω] (ι : K →+* Ω) (n : ℕ+)
    (hn : IsUnit ((n : ℕ) : K)) (x y : Ω) (hx : x ≠ 0)
    (hxy : x ^ (n : ℕ) = y ^ (n : ℕ)) :
    ∃! ζ : rootsOfUnity (n : ℕ) K, ι ((ζ : Kˣ) : K) * x = y