Module

GlobalCompositumCyclotomicTarget.lean

Nyll.ClassFieldTheory.KroneckerWeber.GlobalCompositumCyclotomicTarget
6 declarations indexed from sourceView source ↗

The common local cyclotomic target

At a ramified prime p, the structured local embedding of L has order (p^f - 1) * p^e, while the global conductor has order p^e * c with c prime to p. Their common target has order ((p^f - 1) * c) * p^e; crucially, it uses the same exponent e.

Declarations

KroneckerWeber.kroneckerWeberLocalCompositumCoprimePart

The prime-to-p factor of the common local target.

Source context 4 commands

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

noncomputable section
namespace KroneckerWeber
variable (L : Type) [Field L]
variable [hNF : NumberField L] [hLab : IsAbelianGalois ℚ L]
def kroneckerWeberLocalCompositumCoprimePart
    (p : Nat.Primes) : ℕ
KroneckerWeber.kroneckerWeberLocalCompositumOrder

The common local cyclotomic order, retaining exactly the conductor exponent chosen at p.

Source context 4 commands

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

noncomputable section
namespace KroneckerWeber
variable (L : Type) [Field L]
variable [hNF : NumberField L] [hLab : IsAbelianGalois ℚ L]
def kroneckerWeberLocalCompositumOrder
    (p : Nat.Primes) : ℕ
KroneckerWeber.kroneckerWeberLocalCompositumCoprimePart_coprime

The prime-to-p part of the common local target is coprime to p.

Source context 4 commands

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

noncomputable section
namespace KroneckerWeber
variable (L : Type) [Field L]
variable [hNF : NumberField L] [hLab : IsAbelianGalois ℚ L]
theorem kroneckerWeberLocalCompositumCoprimePart_coprime
    (p : Nat.Primes) :
    Nat.Coprime p.1
      (kroneckerWeberLocalCompositumCoprimePart (L := L) p)
KroneckerWeber.kroneckerWeberLocalCompositumOrder_pos

The common local cyclotomic order is positive.

Source context 4 commands

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

noncomputable section
namespace KroneckerWeber
variable (L : Type) [Field L]
variable [hNF : NumberField L] [hLab : IsAbelianGalois ℚ L]
theorem kroneckerWeberLocalCompositumOrder_pos
    (p : Nat.Primes) :
    0 < kroneckerWeberLocalCompositumOrder (L := L) p
KroneckerWeber.kroneckerWeberLocalStructuredOrder_dvd_compositumOrder

The structured local cyclotomic order divides the common local order.

Source context 4 commands

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

noncomputable section
namespace KroneckerWeber
variable (L : Type) [Field L]
variable [hNF : NumberField L] [hLab : IsAbelianGalois ℚ L]
theorem kroneckerWeberLocalStructuredOrder_dvd_compositumOrder
    (p : Nat.Primes) :
    (p.1 ^ kroneckerWeberLocalUnramifiedDegree (L := L) p - 1) *
        p.1 ^ kroneckerWeberLocalRamificationExponent (L := L) p ∣
      kroneckerWeberLocalCompositumOrder (L := L) p
KroneckerWeber.kroneckerWeberConductorCandidate_dvd_localCompositumOrder

At a ramified prime, the global conductor candidate divides the common local cyclotomic order.

Source context 4 commands

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

noncomputable section
namespace KroneckerWeber
variable (L : Type) [Field L]
variable [hNF : NumberField L] [hLab : IsAbelianGalois ℚ L]
theorem kroneckerWeberConductorCandidate_dvd_localCompositumOrder
    (p : Nat.Primes)
    (hp : p ∈ kroneckerWeberRamifiedPrimes (L := L)) :
    kroneckerWeberConductorCandidate (L := L) ∣
      kroneckerWeberLocalCompositumOrder (L := L) p