def
Subalgebra.conductorIdeal
(R : Type u_1)
(S : Type u_2)
[CommRing R]
[CommRing S]
[Algebra R S]
(A : Subalgebra R S)
:
Ideal S
Instances For
- isNoetherian : IsNoetherianRing O
- dimLEOne : Ring.DimensionLEOne O
- intClosureFG (K : Type u_2) [Field K] [Algebra O K] [IsFractionRing O K] : Module.Finite O ↥(integralClosure O K)
Instances
class
IsAOrder
(A : Type u_1)
(L : Type u_2)
[CommRing A]
[CommRing L]
[Algebra A L]
(O : Subalgebra A L)
:
- fg : (Subalgebra.toSubmodule O).FG
- spans (K : Type u_3) [Field K] [Algebra A K] [IsFractionRing A K] [Algebra K L] [IsScalarTower A K L] : Submodule.span K (Set.range Subtype.val) = ⊤
Instances
theorem
conductor_ne_bot_of_fg_subalgebra
{R : Type u_3}
[CommRing R]
[IsDomain R]
{K : Type u_4}
[Field K]
[Algebra R K]
[IsFractionRing R K]
(S : Subalgebra R K)
(hS : (Subalgebra.toSubmodule S).FG)
:
∃ (d : R), d ≠ 0 ∧ ∀ s ∈ S, (algebraMap R K) d * s ∈ (algebraMap R K).range
theorem
conductor_ne_bot_iff_module_finite
{R : Type u_3}
[CommRing R]
[IsDomain R]
[IsNoetherianRing R]
{K : Type u_4}
[Field K]
[Algebra R K]
[IsFractionRing R K]
(S : Subalgebra R K)
:
(∃ (d : R), d ≠ 0 ∧ ∀ s ∈ S, (algebraMap R K) d * s ∈ (algebraMap R K).range) ↔ (Subalgebra.toSubmodule S).FG
theorem
order_prime_decomposition
{R : Type u_1}
{S : Type u_2}
[CommRing R]
[CommRing S]
[Algebra R S]
{x : S}
{I : Ideal R}
[IsDomain R]
[IsIntegrallyClosed R]
[IsDedekindDomain S]
[Module.IsTorsionFree R S]
(hI : I.IsMaximal)
(hI' : I ≠ ⊥)
(hx : Ideal.comap (algebraMap R S) (conductor R x) ⊔ I = ⊤)
(hx' : IsIntegral R x)
:
have e := KummerDedekind.normalizedFactorsMapEquivNormalizedFactorsMinPolyMk hI hI' hx hx';
∀ {J : Ideal S} (hJ : J ∈ UniqueFactorizationMonoid.normalizedFactors (Ideal.map (algebraMap R S) I)),
emultiplicity J (Ideal.map (algebraMap R S) I) = emultiplicity (↑(e ⟨J, hJ⟩)) (Polynomial.map (Ideal.Quotient.mk I) (minpoly R x))
def
FractionalIdeal.IsPrimeTo
{A : Type u_1}
[CommRing A]
[IsDomain A]
[IsNoetherianRing A]
(I : FractionalIdeal (nonZeroDivisors A) (Localization (nonZeroDivisors A)))
(J : Ideal A)
:
Instances For
def
invertibleFractionalIdealsPrimeTo
{A : Type u_1}
[CommRing A]
[IsDomain A]
[IsNoetherianRing A]
(J : Ideal A)
:
Instances For
class
IsAOrder_AKLB
(A : Type u_1)
(L : Type u_2)
[CommRing A]
[IsDomain A]
[IsNoetherianRing A]
[CommRing L]
[IsDomain L]
[Algebra A L]
(O : Subalgebra A L)
:
- fg : (Subalgebra.toSubmodule O).FG
- spans (K : Type u_3) [Field K] [Algebra A K] [IsFractionRing A K] [Algebra K L] [IsScalarTower A K L] : Submodule.span K (Set.range Subtype.val) = ⊤
Instances
theorem
order_iff_fg_integral
{A : Type u_1}
{K : Type u_2}
{L : Type u_3}
{B : Type u_4}
[CommRing A]
[IsDomain A]
[IsNoetherianRing A]
[IsDedekindDomain A]
[Field K]
[Algebra A K]
[IsFractionRing A K]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra A B]
[CommRing L]
[IsDomain L]
[Algebra A L]
[Algebra K L]
[Algebra B L]
[IsScalarTower A K L]
[IsScalarTower A B L]
[IsIntegralClosure B A L]
[Module.Finite A B]
(O : Subalgebra A L)
[IsFractionRing (↥O) L]
(hA : ¬IsField A)
:
theorem
conductor_span_helper
{O : Type u_1}
{B : Type u_2}
[CommRing O]
[IsDomain O]
[CommRing B]
[IsDomain B]
[Algebra O B]
{𝔠 𝔭 : Ideal O}
(h𝔠_cond : ∀ c ∈ 𝔠, ∀ (b : B), (algebraMap O B) c * b ∈ (algebraMap O B).range)
{s : O}
(hs𝔠 : s ∈ 𝔠)
{x : B}
(hx : x ∈ Ideal.map (algebraMap O B) 𝔭)
:
∃ (n : ℕ), ∃ q ∈ 𝔭, (algebraMap O B) q = (algebraMap O B) s ^ n * x
theorem
ideal_extension_prime_coprime_conductor
{O : Type u_1}
{B : Type u_2}
[CommRing O]
[IsDomain O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra O B]
(hf : Function.Injective ⇑(algebraMap O B))
{𝔠 𝔭 : Ideal O}
[h𝔭 : 𝔭.IsPrime]
(h𝔠_cond : ∀ c ∈ 𝔠, ∀ (b : B), (algebraMap O B) c * b ∈ (algebraMap O B).range)
(h_sup : 𝔠 ⊔ 𝔭 = ⊤)
(h𝔭_not_contain : ¬𝔠 ≤ 𝔭)
:
(Ideal.map (algebraMap O B) 𝔭).IsPrime
theorem
prime_bijection_coprime_conductor
{O : Type u_1}
{B : Type u_2}
[CommRing O]
[IsDomain O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra O B]
(hf : Function.Injective ⇑(algebraMap O B))
(𝔠 : Ideal O)
(h𝔠_ne : 𝔠 ≠ ⊥)
(h𝔠_cond : ∀ c ∈ 𝔠, ∀ (b : B), (algebraMap O B) c * b ∈ (algebraMap O B).range)
(h_sup : ∀ (𝔭 : Ideal O), 𝔭.IsPrime → 𝔭 ≠ ⊥ → ¬𝔠 ≤ 𝔭 → 𝔠 ⊔ 𝔭 = ⊤)
:
∃ (e :
{ 𝔮 : Ideal B // 𝔮.IsPrime ∧ 𝔮 ≠ ⊥ ∧ ¬Ideal.map (algebraMap O B) 𝔠 ≤ 𝔮 } ≃ { 𝔭 : Ideal O // 𝔭.IsPrime ∧ 𝔭 ≠ ⊥ ∧ ¬𝔠 ≤ 𝔭 }),
(∀ (𝔮 : { 𝔮 : Ideal B // 𝔮.IsPrime ∧ 𝔮 ≠ ⊥ ∧ ¬Ideal.map (algebraMap O B) 𝔠 ≤ 𝔮 }),
↑(e 𝔮) = Ideal.comap (algebraMap O B) ↑𝔮) ∧ ∀ (𝔭 : { 𝔭 : Ideal O // 𝔭.IsPrime ∧ 𝔭 ≠ ⊥ ∧ ¬𝔠 ≤ 𝔭 }), ↑(e.symm 𝔭) = Ideal.map (algebraMap O B) ↑𝔭
theorem
localization_equiv_coprime_conductor
{O : Type u_1}
{B : Type u_2}
[CommRing O]
[IsDomain O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra O B]
(𝔠 𝔭 : Ideal O)
[h𝔭 : 𝔭.IsPrime]
(h𝔭_ne : 𝔭 ≠ ⊥)
:
(¬𝔠 ≤ 𝔭 ↔ ∀ (x : B), x ∈ (algebraMap O B).range ↔ ∀ p ∈ 𝔭, x * (algebraMap O B) p ∈ Ideal.map (algebraMap O B) 𝔭) ∧ (¬𝔠 ≤ 𝔭 ↔ IsUnit ↑𝔭) ∧ (¬𝔠 ≤ 𝔭 ↔ IsDiscreteValuationRing (Localization.AtPrime 𝔭)) ∧ (¬𝔠 ≤ 𝔭 ↔ Submodule.IsPrincipal (IsLocalRing.maximalIdeal (Localization.AtPrime 𝔭))) ∧ (¬𝔠 ≤ 𝔭 → (Ideal.map (algebraMap O B) 𝔭).IsPrime)
theorem
extendedHom_isPrimeTo_of_comap
{O : Type u_1}
{B : Type u_2}
[CommRing O]
[IsDomain O]
[IsNoetherianRing O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra O B]
(hf : Function.Injective ⇑(algebraMap O B))
(𝔠 : Ideal B)
(h𝔠_cond : ∀ c ∈ 𝔠, ∀ (b : B), c * b ∈ (algebraMap O B).range)
(hle : nonZeroDivisors O ≤ Submonoid.comap (algebraMap O B) (nonZeroDivisors B))
(u : (FractionalIdeal (nonZeroDivisors O) (Localization (nonZeroDivisors O)))ˣ)
(hu : (↑u).IsPrimeTo (Ideal.comap (algebraMap O B) 𝔠))
:
(↑((Units.map ↑(FractionalIdeal.extendedHom (Localization (nonZeroDivisors B)) hle)) u)).IsPrimeTo 𝔠
theorem
extended_unit_eq_one_coprime_conductor
{O : Type u_1}
{B : Type u_2}
[CommRing O]
[IsDomain O]
[IsNoetherianRing O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra O B]
(hf : Function.Injective ⇑(algebraMap O B))
(𝔠 : Ideal B)
(h𝔠_cond : ∀ c ∈ 𝔠, ∀ (b : B), c * b ∈ (algebraMap O B).range)
(hle : nonZeroDivisors O ≤ Submonoid.comap (algebraMap O B) (nonZeroDivisors B))
(u : (FractionalIdeal (nonZeroDivisors O) (Localization (nonZeroDivisors O)))ˣ)
(hu : (FractionalIdeal.extendedHom (Localization (nonZeroDivisors B)) hle) ↑u = 1)
:
theorem
extendedHom_injective_on_units_order
{O : Type u_1}
{B : Type u_2}
[CommRing O]
[IsDomain O]
[IsNoetherianRing O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra O B]
(hf : Function.Injective ⇑(algebraMap O B))
(𝔠 : Ideal B)
(h𝔠_cond : ∀ c ∈ 𝔠, ∀ (b : B), c * b ∈ (algebraMap O B).range)
(hle : nonZeroDivisors O ≤ Submonoid.comap (algebraMap O B) (nonZeroDivisors B))
:
theorem
surjective_preimage_helper
{O : Type u_1}
{B : Type u_2}
[CommRing O]
[IsDomain O]
[IsNoetherianRing O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra O B]
(hf : Function.Injective ⇑(algebraMap O B))
(𝔠 : Ideal B)
(h𝔠_cond : ∀ c ∈ 𝔠, ∀ (b : B), c * b ∈ (algebraMap O B).range)
(hle : nonZeroDivisors O ≤ Submonoid.comap (algebraMap O B) (nonZeroDivisors B))
(v : ↥(invertibleFractionalIdealsPrimeTo 𝔠))
:
∃ u ∈ invertibleFractionalIdealsPrimeTo (Ideal.comap (algebraMap O B) 𝔠),
(Units.map ↑(FractionalIdeal.extendedHom (Localization (nonZeroDivisors B)) hle)) u = ↑v
theorem
coprime_factorization_surjective_helper
{O : Type u_1}
{B : Type u_2}
[CommRing O]
[IsDomain O]
[IsNoetherianRing O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra O B]
(hf : Function.Injective ⇑(algebraMap O B))
(𝔠 : Ideal B)
(h𝔠_cond : ∀ c ∈ 𝔠, ∀ (b : B), c * b ∈ (algebraMap O B).range)
(hle : nonZeroDivisors O ≤ Submonoid.comap (algebraMap O B) (nonZeroDivisors B))
(v : ↥(invertibleFractionalIdealsPrimeTo 𝔠))
:
∃ (u : ↥(invertibleFractionalIdealsPrimeTo (Ideal.comap (algebraMap O B) 𝔠))),
(Units.map ↑(FractionalIdeal.extendedHom (Localization (nonZeroDivisors B)) hle)) ↑u = ↑v
theorem
coprime_ideal_group_iso
{O : Type u_1}
{B : Type u_2}
[CommRing O]
[IsDomain O]
[IsNoetherianRing O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra O B]
(hf : Function.Injective ⇑(algebraMap O B))
(𝔠 : Ideal B)
(h𝔠_cond : ∀ c ∈ 𝔠, ∀ (b : B), c * b ∈ (algebraMap O B).range)
:
Nonempty
(↥(invertibleFractionalIdealsPrimeTo (Ideal.comap (algebraMap O B) 𝔠)) ≃* ↥(invertibleFractionalIdealsPrimeTo 𝔠))
theorem
coprime_residue_field_iso
{A : Type u_1}
{O : Type u_2}
{B : Type u_3}
[CommRing A]
[IsDomain A]
[IsDedekindDomain A]
[CommRing O]
[IsDomain O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra A O]
[Algebra A B]
[Algebra O B]
[IsScalarTower A O B]
(𝔮 : Ideal B)
[h𝔮 : 𝔮.IsPrime]
(h𝔮_ne : 𝔮 ≠ ⊥)
(𝔠 : Ideal B)
(h𝔮_cond : ¬𝔠 ≤ 𝔮)
(h_conductor : ∀ c ∈ 𝔠, ∀ (b : B), ∃ (o : O), (algebraMap O B) o = c * b)
:
Nonempty (B ⧸ 𝔮 ≃+* O ⧸ Ideal.comap (algebraMap O B) 𝔮)
theorem
coprime_residue_degree_eq
{A : Type u_1}
{O : Type u_2}
{B : Type u_3}
[CommRing A]
[IsDomain A]
[IsDedekindDomain A]
[CommRing O]
[IsDomain O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra A O]
[Algebra A B]
[Algebra O B]
[IsScalarTower A O B]
(𝔮 : Ideal B)
[h𝔮 : 𝔮.IsPrime]
(h𝔮_ne : 𝔮 ≠ ⊥)
(𝔠 : Ideal B)
(h𝔮_cond : ¬𝔠 ≤ 𝔮)
(h_conductor : ∀ c ∈ 𝔠, ∀ (b : B), ∃ (o : O), (algebraMap O B) o = c * b)
:
theorem
coprime_ideal_norm_eq
{A : Type u_1}
{O : Type u_2}
{B : Type u_3}
[CommRing A]
[IsDomain A]
[IsDedekindDomain A]
[CommRing O]
[IsDomain O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra A O]
[Algebra A B]
[Algebra O B]
[IsScalarTower A O B]
(𝔮 : Ideal B)
[h𝔮 : 𝔮.IsPrime]
(h𝔮_ne : 𝔮 ≠ ⊥)
(𝔠 : Ideal B)
(h𝔮_cond : ¬𝔠 ≤ 𝔮)
(h_conductor : ∀ c ∈ 𝔠, ∀ (b : B), ∃ (o : O), (algebraMap O B) o = c * b)
:
theorem
spanNorm_le_of_conductor_coprime
{A : Type u_1}
{O : Type u_2}
{B : Type u_3}
[CommRing A]
[IsDomain A]
[IsDedekindDomain A]
[CommRing O]
[IsDomain O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra A O]
[Algebra A B]
[Algebra O B]
[IsScalarTower A O B]
[Module.Finite A B]
[Module.IsTorsionFree A B]
(𝔮 : Ideal B)
[h𝔮 : 𝔮.IsPrime]
(h𝔮_ne : 𝔮 ≠ ⊥)
(𝔠 : Ideal B)
(_h𝔮_cond : ¬𝔠 ≤ 𝔮)
(h_conductor : ∀ c ∈ 𝔠, ∀ (b : B), ∃ (o : O), (algebraMap O B) o = c * b)
(h_cond_A : ¬Ideal.comap (algebraMap A B) 𝔠 ≤ Ideal.comap (algebraMap A B) 𝔮)
:
Ideal.spanNorm A 𝔮 ≤ Ideal.span (⇑(Algebra.intNorm A B) '' (⇑(algebraMap O B) '' ↑(Ideal.comap (algebraMap O B) 𝔮)))
theorem
coprime_norm_commutes
{A : Type u_1}
{O : Type u_2}
{B : Type u_3}
[CommRing A]
[IsDomain A]
[IsDedekindDomain A]
[CommRing O]
[IsDomain O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra A O]
[Algebra A B]
[Algebra O B]
[IsScalarTower A O B]
[Module.Finite A B]
[Module.IsTorsionFree A B]
(𝔮 : Ideal B)
[h𝔮 : 𝔮.IsPrime]
(h𝔮_ne : 𝔮 ≠ ⊥)
(𝔠 : Ideal B)
(h𝔮_cond : ¬𝔠 ≤ 𝔮)
(h_conductor : ∀ c ∈ 𝔠, ∀ (b : B), ∃ (o : O), (algebraMap O B) o = c * b)
(h_cond_A : ¬Ideal.comap (algebraMap A B) 𝔠 ≤ Ideal.comap (algebraMap A B) 𝔮)
:
Ideal.spanNorm A 𝔮 = Ideal.span (⇑(Algebra.intNorm A B) '' (⇑(algebraMap O B) '' ↑(Ideal.comap (algebraMap O B) 𝔮)))
theorem
order_coprime_prime_properties
{A : Type u_1}
{O : Type u_2}
{B : Type u_3}
[CommRing A]
[IsDomain A]
[IsDedekindDomain A]
[CommRing O]
[IsDomain O]
[CommRing B]
[IsDomain B]
[IsDedekindDomain B]
[Algebra A O]
[Algebra A B]
[Algebra O B]
[IsScalarTower A O B]
[Module.Finite A B]
[Module.IsTorsionFree A B]
[PerfectField (FractionRing A)]
(𝔮 : Ideal B)
[h𝔮 : 𝔮.IsPrime]
(h𝔮_ne : 𝔮 ≠ ⊥)
(𝔠 : Ideal B)
(h𝔮_cond : ¬𝔠 ≤ 𝔮)
(h_conductor : ∀ c ∈ 𝔠, ∀ (b : B), ∃ (o : O), (algebraMap O B) o = c * b)
(h_ext : 𝔠 = Ideal.map (algebraMap A B) (Ideal.comap (algebraMap A B) 𝔠))
:
Nat.card (B ⧸ 𝔮) = Nat.card (O ⧸ Ideal.comap (algebraMap O B) 𝔮) ∧ Submodule.cardQuot 𝔮 = Submodule.cardQuot (Ideal.comap (algebraMap O B) 𝔮) ∧ Ideal.spanNorm A 𝔮 = Ideal.span (⇑(Algebra.intNorm A B) '' (⇑(algebraMap O B) '' ↑(Ideal.comap (algebraMap O B) 𝔮))) ∧ Ideal.spanNorm A 𝔮 = Ideal.comap (algebraMap A B) 𝔮 ^ (Ideal.comap (algebraMap A B) 𝔮).inertiaDeg 𝔮