Coproduct Terms in the Forest Algebra #
This file turns the finite cut-term lists from HopfAlgebras.Cuts.Rooted into elements of
the monoid algebra on pairs of rooted forests. This is a tensor-coded target
for the BCK coproduct: a pair (φ, ψ) represents the basis tensor
φ ⊗ ψ.
The tree coproduct is first defined for planar representatives, then quotiented to non-planar rooted trees and forests.
Main definitions #
ForestTensorAlgebra- monoid algebra on pairs of rooted forestsForestTensorAlgebra.ofForests- basis tensor represented by a pairForestTensorAlgebra.sumTerms- finite sum of basis tensorsPTree.coproduct- planar tree coproduct as a finite algebra elementPTree.coproductList- multiplicative extension to planar forestsRootedTree.coproduct- non-planar tree coproductRootedForest.coproduct- multiplicative extension to non-planar forests
References #
- Alain Connes, Dirk Kreimer, Hopf Algebras, Renormalization and Noncommutative Geometry
- Loic Foissy, An introduction to Hopf algebras of trees
Tensor-coded forest algebra: (φ, ψ) represents the basis tensor φ ⊗ ψ.
Equations
Instances For
The basis tensor represented by a pair of rooted forests.
Equations
Instances For
The basis tensor φ ⊗ ψ.
Equations
Instances For
Sum a finite list of basis tensors. Duplicates contribute multiplicity.
Equations
Instances For
Apply the counit to the left tensor factor.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Apply the counit to the right tensor factor.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Triple tensor-coded forest algebra:
(φ, ψ, η) represents the basis tensor φ ⊗ ψ ⊗ η.
Equations
Instances For
The basis triple tensor represented by a triple of rooted forests.
Equations
Instances For
The basis tensor φ ⊗ ψ ⊗ η.
Equations
Instances For
Sum a finite list of basis triple tensors. Duplicates contribute multiplicity.
Equations
Instances For
Multiply two finite lists of triple tensor basis terms.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Embed a pair tensor as the first two factors of a triple tensor.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Embed a pair tensor as the last two factors of a triple tensor.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The planar BCK coproduct of a tree, represented in the tensor-coded algebra.
Instances For
The reduced planar BCK coproduct, summing only proper cut terms.
Instances For
Multiplicative extension of the planar coproduct to planar forests.
Equations
Instances For
The reduced planar BCK coproduct of a planar forest.
Equations
Instances For
The BCK coproduct of a non-planar rooted tree.
Equations
Instances For
The reduced BCK coproduct of a non-planar rooted tree.
Equations
Instances For
A finite representative list for the forest coproduct, using Quotient.out.
Equations
Instances For
The only forest coproduct terms with empty left factor are 1 ⊗ φ.
The only forest coproduct terms with empty right factor are φ ⊗ 1.
The forest coproduct has exactly one term with empty left factor.
The forest coproduct has exactly one term with empty right factor.
A finite representative list for the reduced forest coproduct.
Equations
- φ.properCoproductTerms = List.filter (fun (term : HopfAlgebras.RootedForest × HopfAlgebras.RootedForest) => decide (0 < term.1.order ∧ 0 < term.2.order)) φ.coproductTerms
Instances For
The multiplicative coproduct of a non-planar rooted forest.
Equations
- φ.coproduct = Quotient.lift (fun (ts : List HopfAlgebras.RootedTree) => HopfAlgebras.PTree.coproductList (List.map Quotient.out ts)) ⋯ φ
Instances For
The reduced BCK coproduct of a non-planar rooted forest.
Instances For
Apply the coproduct to the first tensor factor, the map Δ ⊗ id.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Apply the coproduct to the second tensor factor, the map id ⊗ Δ.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Equations
- HopfAlgebras.ForestTripleTensorAlgebra.coproductLeftTerm term = List.map (fun (left : HopfAlgebras.RootedForest × HopfAlgebras.RootedForest) => (left.1, left.2, term.2)) term.1.coproductTerms
Instances For
Equations
- One or more equations did not get rendered due to their size.
Instances For
Equations
Instances For
Equations
Instances For
The BCK coproduct as an algebra morphism on the rooted-forest algebra.
Equations
Instances For
The iterated coproduct (Δ ⊗ id) ∘ Δ.
Equations
Instances For
The iterated coproduct (id ⊗ Δ) ∘ Δ.