Module

PadicCharacterSurjectivity.lean

Nyll.GaloisCohomology.ProfiniteIntegers.PadicCharacterSurjectivity
1 declaration indexed from sourceView source ↗

Surjectivity of p-adic characters detected modulo p

Declarations

PadicInt.surjective_character_of_nonzero_reduction

A compact-group character in the additive p-adic integers is surjective when its reduction modulo p is nonzero. Its closed image contains the dense integer multiples of a p-adic unit.

Source context 4 commands

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

namespace PadicInt
universe u
variable {p : ℕ} [Fact p.Prime]
variable {G : Type u} [Group G] [TopologicalSpace G] [CompactSpace G]
theorem surjective_character_of_nonzero_reduction
    (χ : G →ₜ* Multiplicative (PadicInt p))
    (hχ : ∃ g : G, toZModPow 1 (χ g).toAdd ≠ 0) :
    Function.Surjective χ