Module

PClassGroup.lean

Nyll.SawinTotallyRealTowers.UnramifiedProPRelationRank.Global.PClassGroup
6 declarations indexed from sourceView source ↗

The elementary p-class quotient

This file defines the ordinary ideal class group modulo pth powers and its canonical dimension over ZMod p when p is prime.

Declarations

ClassFieldTower.Martinet.pClassPowerSubgroup

The subgroup of pth powers in the ordinary ideal class group.

Source context 5 commands

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

open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet
open ClassFieldTower.ProP
variable (K : Type*) [Field K] [NumberField K]
def pClassPowerSubgroup (p : ℕ) : Subgroup (ClassGroup (𝓞 K))
ClassFieldTower.Martinet.pClassPowerSubgroup_normal
Source context 5 commands

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

open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet
open ClassFieldTower.ProP
variable (K : Type*) [Field K] [NumberField K]
instance pClassPowerSubgroup_normal (p : ℕ) :
    (pClassPowerSubgroup K p).Normal
ClassFieldTower.Martinet.PClassGroup

The ordinary ideal class group modulo pth powers.

Source context 6 commands

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

open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet
open ClassFieldTower.ProP
variable (K : Type*) [Field K] [NumberField K]
local instance pClassPowerSubgroup_normal (p : ℕ) :
    (pClassPowerSubgroup K p).Normal := inferInstance
abbrev PClassGroup (p : ℕ)
ClassFieldTower.Martinet.pClassGroup_pow_eq_one

Every element of the p-class quotient has exponent dividing p.

Source context 7 commands

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

open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet
open ClassFieldTower.ProP
variable (K : Type*) [Field K] [NumberField K]
local instance pClassPowerSubgroup_normal (p : ℕ) :
    (pClassPowerSubgroup K p).Normal := inferInstance
omit [NumberField K] in
theorem pClassGroup_pow_eq_one (p : ℕ) (x : PClassGroup K p) :
    x ^ p = 1
ClassFieldTower.Martinet.pClassRank

The canonical ZMod p-dimension of the ordinary ideal class group modulo pth powers.

Source context 6 commands

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

open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet
open ClassFieldTower.ProP
variable (K : Type*) [Field K] [NumberField K]
local instance pClassPowerSubgroup_normal (p : ℕ) :
    (pClassPowerSubgroup K p).Normal := inferInstance
def pClassRank (p : ℕ) [Fact p.Prime] : ℕ
ClassFieldTower.Martinet.powerSubgroup_map_mulEquiv

A multiplicative equivalence carries the power subgroup onto the power subgroup.

Source context 6 commands

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

open scoped NumberField
noncomputable section
namespace ClassFieldTower.Martinet
open ClassFieldTower.ProP
variable (K : Type*) [Field K] [NumberField K]
local instance pClassPowerSubgroup_normal (p : ℕ) :
    (pClassPowerSubgroup K p).Normal := inferInstance
theorem powerSubgroup_map_mulEquiv
    {G H : Type*} [Group G] [Group H] (p : ℕ) (e : G ≃* H) :
    (powerSubgroup p G).map e.toMonoidHom = powerSubgroup p H