OAI/RepresentationTheory/FoulkesHowe/BlockWeight.lean
17 declarations, 0 contain sorry, 0 declared as axioms
- def
OAI.Problem346.PolynomialWeights.weightedEulerline 16Source documentation
The Euler derivation associated with natural-number weights.
def weightedEuler (w : σ → ℕ) : Derivation R (MvPolynomial σ R) (MvPolynomial σ R) := … - theorem
OAI.Problem346.PolynomialWeights.weightedEuler_applyline 20 - theorem
OAI.Problem346.PolynomialWeights.weightedEuler_Xline 28 - theorem
OAI.Problem346.PolynomialWeights.weightedEuler_of_homogeneousline 34Source documentation
Euler's identity, expressed using a bundled derivation.
theorem weightedEuler_of_homogeneous (w : σ → ℕ) {n : ℕ} {f : MvPolynomial σ R} (hf : f.IsWeightedHomogeneous w n) : weightedEuler w f = n • f := by … - theorem
OAI.Problem346.PolynomialWeights.derivation_eq_weightedEulerline 41Source documentation
Any derivation with the prescribed diagonal action on generators is Euler.
theorem derivation_eq_weightedEuler (w : σ → ℕ) (N : Derivation R (MvPolynomial σ R) (MvPolynomial σ R)) (hN : ∀ i, N (X i) = w i • X i) : N = weightedEuler w := by … - theorem
OAI.Problem346.PolynomialWeights.derivation_homogeneous_eigenvalueline 49Source documentation
A homogeneous polynomial is an eigenvector for its weighted Euler derivation.
theorem derivation_homogeneous_eigenvalue (w : σ → ℕ) (N : Derivation R (MvPolynomial σ R) (MvPolynomial σ R)) (hN : ∀ i, N (X i) = w i • X i) {n : ℕ} {f : MvPolynomial σ R} (hf : f.IsWeightedHomogeneous w n) : N f = n • f := by … - def
OAI.Problem346.PolynomialWeights.blockWeightline 62Source documentation
Weight one on one coordinate block, and zero on all spectator blocks.
def blockWeight (u : β) (ki : β × ι) : ℕ := if ki.1 = u then 1 else 0
- def
OAI.Problem346.PolynomialWeights.IsBlockHomogeneousline 65Source documentation
A polynomial is homogeneous of the specified degree in one block.
def IsBlockHomogeneous (u : β) (f : MvPolynomial (β × ι) R) (n : ℕ) : Prop := …
- theorem
OAI.Problem346.PolynomialWeights.blockWeight_applyline 69 - theorem
OAI.Problem346.PolynomialWeights.block_euler_eigenvalueline 72 - theorem
OAI.Problem346.PolynomialWeights.block_difference_eigenvalueline 84Source documentation
The difference of block counting operators has the difference of the block degrees as eigenvalue. This is the weight used by the positive-weight shift lemma.
theorem block_difference_eigenvalue (u v : β) (Nu Nv : Derivation ℂ (MvPolynomial (β × ι) ℂ) (MvPolynomial (β × ι) ℂ)) (hu : ∀ k i, Nu (X (k, i)) = if k = u then X (k, i) else 0) (hv : ∀ k i, Nv (X (k, i)) = if k = v then X (k, i) else 0) {p q : ℕ} {f : MvPolynomial (β × ι) ℂ} (hp : IsBlockHomogeneous u f p) (hq : IsBlockHomogeneous v f q) : (Nu - Nv) f = ((p : ℂ) - (q : ℂ)) • f := by …Mentions: OAI.Problem346.PolynomialWeights.IsBlockHomogeneous
- theorem
OAI.Problem346.PolynomialWeights.block_difference_nat_eigenvalueline 96 - theorem
OAI.Problem346.PolynomialWeights.block_pderiv_sourceline 108Source documentation
Differentiating in a block lowers its degree by one, provided that degree is positive.
theorem block_pderiv_source {u : β} {n : ℕ} {f : MvPolynomial (β × ι) R} (hf : IsBlockHomogeneous u f n) (hn : 0 < n) (i : ι) : IsBlockHomogeneous u (pderiv (u, i) f) (n - 1) := by …Mentions: OAI.Problem346.PolynomialWeights.IsBlockHomogeneous
- theorem
OAI.Problem346.PolynomialWeights.block_pderiv_otherline 117Source documentation
Differentiating in another block leaves the indicated block degree unchanged.
theorem block_pderiv_other {u k : β} (hku : k ≠ u) {n : ℕ} {f : MvPolynomial (β × ι) R} (hf : IsBlockHomogeneous u f n) (i : ι) : IsBlockHomogeneous u (pderiv (k, i) f) n := by …Mentions: OAI.Problem346.PolynomialWeights.IsBlockHomogeneous
- theorem
OAI.Problem346.PolynomialWeights.block_shift_degree_sourceline 125Source documentation
A directional shift lowers its source block degree by one.
theorem block_shift_degree_source {u v : β} (huv : u ≠ v) {n : ℕ} {f : MvPolynomial (β × ι) R} (hf : IsBlockHomogeneous u f n) (hn : 0 < n) : IsBlockHomogeneous u (∑ i : ι, X (v, i) * pderiv (u, i) f) (n - 1) := by …Mentions: OAI.Problem346.PolynomialWeights.IsBlockHomogeneous
- theorem
OAI.Problem346.PolynomialWeights.block_shift_degree_destinationline 138Source documentation
A directional shift raises its destination block degree by one.
theorem block_shift_degree_destination {u v : β} (huv : u ≠ v) {n : ℕ} {f : MvPolynomial (β × ι) R} (hf : IsBlockHomogeneous v f n) : IsBlockHomogeneous v (∑ i : ι, X (v, i) * pderiv (u, i) f) (n + 1) := by …Mentions: OAI.Problem346.PolynomialWeights.IsBlockHomogeneous
- theorem
OAI.Problem346.PolynomialWeights.block_shift_degree_spectatorline 151Source documentation
A directional shift leaves every spectator block degree unchanged.
theorem block_shift_degree_spectator {u v k : β} (huk : u ≠ k) (hvk : v ≠ k) {n : ℕ} {f : MvPolynomial (β × ι) R} (hf : IsBlockHomogeneous k f n) : IsBlockHomogeneous k (∑ i : ι, X (v, i) * pderiv (u, i) f) n := by …Mentions: OAI.Problem346.PolynomialWeights.IsBlockHomogeneous