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TauCeti.Algebra.Lie.UniversalEnveloping.Kostant.RootSubgroup.Scheme.Generated.Relations

Chevalley relations in the generated Kostant group scheme #

The represented Kostant root subgroups factor through the closed group scheme they generate. This file proves that the factored root subgroups satisfy their Chevalley relations intrinsically in that generated carrier. The earlier matrix and scheme-point relations only identify the images of these points in GLₙ; the closed immersion of the generated group scheme makes the map on points injective, so those identities descend uniquely.

The results are stated on points over every commutative ring A : Type. Commuting root vectors give commuting generated-group points, while a class-two root string ⁅eᵢ, eⱼ⁆ = c • eₖ gives

[xᵢ(s), xⱼ(t)] = xₖ(cst).

The file also transports the multiply-laced relation from Scheme/MultiplyLacedRelations.lean and the type-G₂ relation from Scheme/Relations/G2/Basic.lean, together with its short-pair counterpart in Scheme/Relations/G2/ShortPair.lean. All these relations hold intrinsically on the kostantRootSubgroupToGenerated interface.

Main declarations #

References #

theorem TauCeti.UniversalEnvelopingAlgebra.commute_kostantRootSubgroupToGenerated {L : Type u} [LieRing L] [LieAlgebra ℚ L] {I : Type w} {κ : Type u_1} {V : Type} [AddCommGroup V] [Module ℚ V] (e : I → L) (h : κ → L) (ρ : UniversalEnvelopingAlgebra ℚ L →ₐ[ℚ] Module.End ℚ V) (M : AddSubgroup V) (hM : ∀ u ∈ kostantForm e h, ∀ v ∈ M, (ρ u) v ∈ M) {n : ℕ} (b : Module.Basis (Fin n) ℤ ↥M) (hnil : ∀ (i : I), IsNilpotent (ρ ((UniversalEnvelopingAlgebra.ι ℚ) (e i)))) (A : Type) [CommRing A] {i j : I} (hij : ⁅e i, e j⁆ = 0) (p q : (AlgebraicGeometry.Spec ↧A).asOver (AlgebraicGeometry.Spec ↧ℤ) ⟶ (AdditiveGroup.groupScheme ℤ).X) :

Represented Kostant root subgroups attached to commuting root vectors commute as points of the generated group scheme over every commutative value ring.

The class-two Chevalley commutator relation inside the generated Kostant group scheme. Suppose ⁅eᵢ, eⱼ⁆ = c • eₖ, with eₖ commuting with both eᵢ and eⱼ. If the additive parameter of r is c times the product of those of p and q, then the commutator of the factored i- and j-root points is the factored k-root point at r.

@[simp]

The class-two Chevalley commutator relation inside the generated group scheme, with the third point written explicitly at parameter c times the product of the first two parameters.

theorem TauCeti.UniversalEnvelopingAlgebra.commutatorElement_kostantRootSubgroupToGenerated_of_lie_lie_eq {L : Type u} [LieRing L] [LieAlgebra ℚ L] {I : Type w} {κ : Type u_1} {V : Type} [AddCommGroup V] [Module ℚ V] (e : I → L) (h : κ → L) (ρ : UniversalEnvelopingAlgebra ℚ L →ₐ[ℚ] Module.End ℚ V) (M : AddSubgroup V) (hM : ∀ u ∈ kostantForm e h, ∀ v ∈ M, (ρ u) v ∈ M) {n : ℕ} (b : Module.Basis (Fin n) ℤ ↥M) (hnil : ∀ (i : I), IsNilpotent (ρ ((UniversalEnvelopingAlgebra.ι ℚ) (e i)))) (A : Type) [CommRing A] {i j k l : I} {c d : ℤ} (hij : ⁅e i, e j⁆ = c • e k) (hiij : ⁅e i, ⁅e i, e j⁆⁆ = (2 * d) • e l) (hil : ⁅e i, e l⁆ = 0) (hjk : ⁅e j, e k⁆ = 0) (hjl : ⁅e j, e l⁆ = 0) (hkl : ⁅e k, e l⁆ = 0) (p q r s : (AlgebraicGeometry.Spec ↧A).asOver (AlgebraicGeometry.Spec ↧ℤ) ⟶ (AdditiveGroup.groupScheme ℤ).X) (hr : Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) r) = ↑c * (Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) p) * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) q))) (hs : Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) s) = ↑d * (Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) p) ^ 2 * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) q))) :

The multiply-laced Chevalley commutator relation inside the generated Kostant group scheme. The indices i, j, k, l correspond to α, β, α + β, 2α + β. If r and s have parameters c t u and d t² u, then the commutator of the factored i- and j-root points is the product of the factored k- and l-root points.

theorem TauCeti.UniversalEnvelopingAlgebra.commutatorElement_kostantRootSubgroupToGenerated_of_lie_lie_eq' {L : Type u} [LieRing L] [LieAlgebra ℚ L] {I : Type w} {κ : Type u_1} {V : Type} [AddCommGroup V] [Module ℚ V] (e : I → L) (h : κ → L) (ρ : UniversalEnvelopingAlgebra ℚ L →ₐ[ℚ] Module.End ℚ V) (M : AddSubgroup V) (hM : ∀ u ∈ kostantForm e h, ∀ v ∈ M, (ρ u) v ∈ M) {n : ℕ} (b : Module.Basis (Fin n) ℤ ↥M) (hnil : ∀ (i : I), IsNilpotent (ρ ((UniversalEnvelopingAlgebra.ι ℚ) (e i)))) (A : Type) [CommRing A] {i j k l : I} {c d : ℤ} (hij : ⁅e i, e j⁆ = c • e k) (hiij : ⁅e i, ⁅e i, e j⁆⁆ = (2 * d) • e l) (hil : ⁅e i, e l⁆ = 0) (hjk : ⁅e j, e k⁆ = 0) (hjl : ⁅e j, e l⁆ = 0) (hkl : ⁅e k, e l⁆ = 0) (p q : (AlgebraicGeometry.Spec ↧A).asOver (AlgebraicGeometry.Spec ↧ℤ) ⟶ (AdditiveGroup.groupScheme ℤ).X) :

The multiply-laced Chevalley commutator relation inside the generated group scheme, with both output points written explicitly at parameters c t u and d t² u.

theorem TauCeti.UniversalEnvelopingAlgebra.kostantRootSubgroupToGenerated_mul_of_lie_eq_three_nsmul {L : Type u} [LieRing L] [LieAlgebra ℚ L] {I : Type w} {κ : Type u_1} {V : Type} [AddCommGroup V] [Module ℚ V] (e : I → L) (h : κ → L) (ρ : UniversalEnvelopingAlgebra ℚ L →ₐ[ℚ] Module.End ℚ V) (M : AddSubgroup V) (hM : ∀ u ∈ kostantForm e h, ∀ v ∈ M, (ρ u) v ∈ M) {n : ℕ} (b : Module.Basis (Fin n) ℤ ↥M) (hnil : ∀ (i : I), IsNilpotent (ρ ((UniversalEnvelopingAlgebra.ι ℚ) (e i)))) (A : Type) [CommRing A] {i j k l m o : I} {c d a b' : ℤ} (hij : ⁅e i, e j⁆ = c • e k) (hik : c • ⁅e i, e k⁆ = (2 * d) • e l) (hil : d • ⁅e i, e l⁆ = (3 * a) • e m) (hlk : (d * c) • ⁅e l, e k⁆ = (3 * b') • e o) (him : ⁅e i, e m⁆ = 0) (hio : ⁅e i, e o⁆ = 0) (hjk : ⁅e j, e k⁆ = 0) (hlm : ⁅e l, e m⁆ = 0) (hko : ⁅e k, e o⁆ = 0) (hlo : ⁅e l, e o⁆ = 0) (hmo : ⁅e m, e o⁆ = 0) (f g p q r s : (AlgebraicGeometry.Spec ↧A).asOver (AlgebraicGeometry.Spec ↧ℤ) ⟶ (AdditiveGroup.groupScheme ℤ).X) (hp : Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) p) = ↑c * (Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) f) * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) g))) (hq : Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) q) = ↑d * (Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) f) ^ 2 * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) g))) (hr : Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) r) = ↑a * (Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) f) ^ 3 * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) g))) (hs : Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) s) = ↑b' * (Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) f) ^ 3 * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) g) ^ 2)) :

The type-G₂ Chevalley product relation inside the generated Kostant group scheme. The indices i, j, k, l, m, o correspond to α, β, α + β, 2α + β, 3α + β, 3α + 2β. The four supplied output points have parameters c t u, d t² u, a t³ u, and b t³ u².

theorem TauCeti.UniversalEnvelopingAlgebra.kostantRootSubgroupToGenerated_mul_of_lie_eq_three_nsmul' {L : Type u} [LieRing L] [LieAlgebra ℚ L] {I : Type w} {κ : Type u_1} {V : Type} [AddCommGroup V] [Module ℚ V] (e : I → L) (h : κ → L) (ρ : UniversalEnvelopingAlgebra ℚ L →ₐ[ℚ] Module.End ℚ V) (M : AddSubgroup V) (hM : ∀ u ∈ kostantForm e h, ∀ v ∈ M, (ρ u) v ∈ M) {n : ℕ} (b : Module.Basis (Fin n) ℤ ↥M) (hnil : ∀ (i : I), IsNilpotent (ρ ((UniversalEnvelopingAlgebra.ι ℚ) (e i)))) (A : Type) [CommRing A] {i j k l m o : I} {c d a b' : ℤ} (hij : ⁅e i, e j⁆ = c • e k) (hik : c • ⁅e i, e k⁆ = (2 * d) • e l) (hil : d • ⁅e i, e l⁆ = (3 * a) • e m) (hlk : (d * c) • ⁅e l, e k⁆ = (3 * b') • e o) (him : ⁅e i, e m⁆ = 0) (hio : ⁅e i, e o⁆ = 0) (hjk : ⁅e j, e k⁆ = 0) (hlm : ⁅e l, e m⁆ = 0) (hko : ⁅e k, e o⁆ = 0) (hlo : ⁅e l, e o⁆ = 0) (hmo : ⁅e m, e o⁆ = 0) (f g : (AlgebraicGeometry.Spec ↧A).asOver (AlgebraicGeometry.Spec ↧ℤ) ⟶ (AdditiveGroup.groupScheme ℤ).X) :
CategoryTheory.CategoryStruct.comp f (kostantRootSubgroupToGenerated e h ρ M hM hnil b i).hom.hom * CategoryTheory.CategoryStruct.comp g (kostantRootSubgroupToGenerated e h ρ M hM hnil b j).hom.hom = CategoryTheory.CategoryStruct.comp g (kostantRootSubgroupToGenerated e h ρ M hM hnil b j).hom.hom * CategoryTheory.CategoryStruct.comp ((AdditiveGroup.schemePointsMulEquiv A).symm (Multiplicative.ofAdd (↑c * (Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) f) * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) g))))) (kostantRootSubgroupToGenerated e h ρ M hM hnil b k).hom.hom * CategoryTheory.CategoryStruct.comp ((AdditiveGroup.schemePointsMulEquiv A).symm (Multiplicative.ofAdd (↑d * (Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) f) ^ 2 * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) g))))) (kostantRootSubgroupToGenerated e h ρ M hM hnil b l).hom.hom * CategoryTheory.CategoryStruct.comp ((AdditiveGroup.schemePointsMulEquiv A).symm (Multiplicative.ofAdd (↑a * (Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) f) ^ 3 * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) g))))) (kostantRootSubgroupToGenerated e h ρ M hM hnil b m).hom.hom * CategoryTheory.CategoryStruct.comp ((AdditiveGroup.schemePointsMulEquiv A).symm (Multiplicative.ofAdd (↑b' * (Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) f) ^ 3 * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) g) ^ 2)))) (kostantRootSubgroupToGenerated e h ρ M hM hnil b o).hom.hom * CategoryTheory.CategoryStruct.comp f (kostantRootSubgroupToGenerated e h ρ M hM hnil b i).hom.hom

The type-G₂ Chevalley product relation inside the generated group scheme with the four output points written explicitly at parameters c t u, d t² u, a t³ u, and b t³ u².

theorem TauCeti.UniversalEnvelopingAlgebra.kostantRootSubgroupToGenerated_mul_of_g2_short_pair {L : Type u} [LieRing L] [LieAlgebra ℚ L] {I : Type w} {κ : Type u_1} {V : Type} [AddCommGroup V] [Module ℚ V] (e : I → L) (h : κ → L) (ρ : UniversalEnvelopingAlgebra ℚ L →ₐ[ℚ] Module.End ℚ V) (M : AddSubgroup V) (hM : ∀ u ∈ kostantForm e h, ∀ v ∈ M, (ρ u) v ∈ M) {n : ℕ} (b : Module.Basis (Fin n) ℤ ↥M) (hnil : ∀ (i : I), IsNilpotent (ρ ((UniversalEnvelopingAlgebra.ι ℚ) (e i)))) (A : Type) [CommRing A] {i j k l m : I} {c d a : ℤ} (hij : ⁅e i, e j⁆ = (2 * c) • e k) (hik : c • ⁅e i, e k⁆ = (3 * d) • e l) (hkj : c • ⁅e k, e j⁆ = (3 * a) • e m) (hil : ⁅e i, e l⁆ = 0) (him : ⁅e i, e m⁆ = 0) (hjm : ⁅e j, e m⁆ = 0) (hkl : ⁅e k, e l⁆ = 0) (hkm : ⁅e k, e m⁆ = 0) (hlm : ⁅e l, e m⁆ = 0) (f g p q r : (AlgebraicGeometry.Spec ↧A).asOver (AlgebraicGeometry.Spec ↧ℤ) ⟶ (AdditiveGroup.groupScheme ℤ).X) (hp : Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) p) = ↑c * (2 * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) f) * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) g))) (hq : Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) q) = ↑d * (3 * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) f) ^ 2 * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) g))) (hr : Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) r) = ↑a * (3 * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) f) * Multiplicative.toAdd ((AdditiveGroup.schemePointsMulEquiv A) g) ^ 2)) :

The G₂ short-pair relation inside the generated group scheme, with the output points at parameters 2ctu, 3dt²u, and 3atu². The indices i, j, k, l, m correspond to α, α + β, 2α + β, 3α + β, 3α + 2β.

theorem TauCeti.UniversalEnvelopingAlgebra.kostantRootSubgroupToGenerated_mul_of_g2_short_pair' {L : Type u} [LieRing L] [LieAlgebra ℚ L] {I : Type w} {κ : Type u_1} {V : Type} [AddCommGroup V] [Module ℚ V] (e : I → L) (h : κ → L) (ρ : UniversalEnvelopingAlgebra ℚ L →ₐ[ℚ] Module.End ℚ V) (M : AddSubgroup V) (hM : ∀ u ∈ kostantForm e h, ∀ v ∈ M, (ρ u) v ∈ M) {n : ℕ} (b : Module.Basis (Fin n) ℤ ↥M) (hnil : ∀ (i : I), IsNilpotent (ρ ((UniversalEnvelopingAlgebra.ι ℚ) (e i)))) (A : Type) [CommRing A] {i j k l m : I} {c d a : ℤ} (hij : ⁅e i, e j⁆ = (2 * c) • e k) (hik : c • ⁅e i, e k⁆ = (3 * d) • e l) (hkj : c • ⁅e k, e j⁆ = (3 * a) • e m) (hil : ⁅e i, e l⁆ = 0) (him : ⁅e i, e m⁆ = 0) (hjm : ⁅e j, e m⁆ = 0) (hkl : ⁅e k, e l⁆ = 0) (hkm : ⁅e k, e m⁆ = 0) (hlm : ⁅e l, e m⁆ = 0) (f g : (AlgebraicGeometry.Spec ↧A).asOver (AlgebraicGeometry.Spec ↧ℤ) ⟶ (AdditiveGroup.groupScheme ℤ).X) :

The G₂ short-pair product relation inside the generated group scheme, with the three output points written explicitly at parameters 2ctu, 3dt²u, and 3atu².