Module

StandardSubgroup.lean

Nyll.ClassFieldTheory.LocalClassFieldTheory.Finite.CyclotomicNorm.StandardSubgroup
1 declaration indexed from sourceView source ↗

Standard p-adic norm-subgroup intersections

The p-adic prime element used by the cyclotomic norm calculation has normalized valuation -1. This file records the corresponding orientation of the standard unramified/principal-unit intersection lemma.

Declarations

LocalClassFieldTheory.unramifiedNormSubgroup_inf_padicPrincipalSubgroup_le

The intersection of the degree-f unramified condition and the depth-n principal-unit condition is contained in the standard p-adic subgroup with prime exponent f.

Source context 5 commands

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

noncomputable section
namespace LocalClassFieldTheory
open LocalFieldTheory
open LocalFieldTheory.Padic
open LocalFieldTheory.IsNonarchimedeanLocalField
theorem unramifiedNormSubgroup_inf_padicPrincipalSubgroup_le
    (p f n : ℕ) [Fact p.Prime]
    [IsNonarchimedeanLocalField ℚ_[p]] :
    unramifiedNormSubgroup ℚ_[p] f ⊓
        LocalFieldTheory.uniformizerPrincipalSubgroup ℚ_[p] (padicPrimeUnit p) 1 n ≤
      LocalFieldTheory.uniformizerPrincipalSubgroup ℚ_[p] (padicPrimeUnit p) f n