Recoupling three signed ladder modules #
There are two normalized decompositions of a triple tensor product L_m^ε ⊗ L_n^δ ⊗ L_p^ζ at a
generic parameter q: first decompose the left pair (clebschGordanLeftEquiv), or first decompose
the right pair (clebschGordanRightEquiv). clebschGordanRecouplingEquiv changes between their
channel coordinates through the coproduct tensor associator BialgebraModule.assoc, without
choosing any additional normalizations beyond clebschGordanInclusion.
Main definitions and results #
clebschGordanLeftInclusion,clebschGordanRightInclusion,clebschGordanLeftProjection,clebschGordanRightProjection: normalized triple-product channel inclusions and projections.recouplingHom,invRecouplingHom: channel-to-channel recoupling intertwiners throughassocandassoc.symm.recouplingCoeff,invRecouplingCoeff: Schur scalars ofrecouplingHomandinvRecouplingHom, governing their action on every ladder vectorv_l(recouplingHom_vec,invRecouplingHom_vec) and vanishing on mismatched channel weights.assoc_clebschGordanLeftInclusion_vec,assoc_symm_clebschGordanRightInclusion_vec: explicit triple-product expansions ofassocandassoc.symmon every channel ladder vectorv_l.sum_invRecouplingCoeff_mul_recouplingCoeff,sum_recouplingCoeff_mul_invRecouplingCoeff: channel-summed orthogonality ofrecouplingCoeffandinvRecouplingCoeff.
References #
- C. Kassel, Quantum Groups, Graduate Texts in Mathematics 155, Chapters VII and XII, for Clebsch–Gordan decompositions and recoupling.
The normalized decomposition of the left-associated triple tensor product.
Instances For
The normalized decomposition of the right-associated triple tensor product.
Instances For
On one left channel the decomposition is the composite of its two normalized Clebsch–Gordan inclusions, tensoring the first inclusion with the identity.
On one right channel the decomposition is the composite of its two normalized
Clebsch–Gordan inclusions, tensoring the identity on L_m^ε with the right-pair inclusion.
Right-associated channel extraction is the composite of the two binary projections.
Left-associated channel extraction is the composite of the two binary projections.
Change from left-pair-first to right-pair-first Clebsch–Gordan coordinates, through the actual coproduct tensor associator. All three signs and highest weights are arbitrary.
Instances For
Recoupling followed by the right decomposition is the reassociated left decomposition.
Inverse recoupling followed by the left decomposition undoes reassociation of the right decomposition.
A recoupling coordinate is obtained by including its left channel, reassociating, and then projecting onto the right channel. This fixes the normalization of every entry.
An inverse recoupling coordinate is obtained by including its right channel, undoing reassociation, and then projecting onto the left channel.
Triple-product channel inclusions, projections, and recoupling intertwiners #
Inclusion of the (i, j) left-associated channel into (L_m^ε ⊗ L_n^δ) ⊗ L_p^ζ.
Instances For
Definitional composite formula for clebschGordanLeftInclusion.
Inclusion of the (r, s) right-associated channel into L_m^ε ⊗ (L_n^δ ⊗ L_p^ζ).
Instances For
Definitional composite formula for clebschGordanRightInclusion.
Projection of (L_m^ε ⊗ L_n^δ) ⊗ L_p^ζ onto its (i, j) left-associated channel.
Instances For
Definitional composite formula for clebschGordanLeftProjection.
Projection of L_m^ε ⊗ (L_n^δ ⊗ L_p^ζ) onto its (r, s) right-associated channel.
Instances For
Definitional composite formula for clebschGordanRightProjection.
clebschGordanLeftInclusion agrees with clebschGordanLeftEquiv on a single channel.
clebschGordanRightInclusion agrees with clebschGordanRightEquiv on a single channel.
clebschGordanLeftProjection extracts (i, j) of (clebschGordanLeftEquiv).symm.
clebschGordanRightProjection extracts (r, s) of (clebschGordanRightEquiv).symm.
clebschGordanLeftInclusion sends v₀ to the left-coupled α₀ = 1 highest-weight vector.
clebschGordanRightInclusion sends v₀ to the right-coupled α₀ = 1 highest-weight vector.
On an outer j = 0 channel, clebschGordanLeftInclusion sends v₀ to w_i ⊗ v₀.
On an outer s = 0 channel, clebschGordanRightInclusion sends v₀ to v₀ ⊗ w_r.
Left channel projection is a left inverse to left channel inclusion.
Right channel projection is a left inverse to right channel inclusion.
Distinct left-associated channels are annihilated by clebschGordanLeftProjection.
Distinct right-associated channels are annihilated by clebschGordanRightProjection.
Composing a left channel projection with its left channel inclusion gives LinearMap.id.
Composing a right channel projection with its right channel inclusion gives LinearMap.id.
Composing a left channel projection with a distinct left channel inclusion gives 0.
Composing a right channel projection with a distinct right channel inclusion gives 0.
Channel-to-channel recoupling intertwiner (i, j) → (r, s) through BialgebraModule.assoc.
Instances For
Definitional composite formula for recouplingHom.
Inverse recoupling intertwiner (r, s) → (i, j) through (BialgebraModule.assoc).symm.
Instances For
Definitional composite formula for invRecouplingHom.
recouplingHom agrees with coordinate (r, s) of clebschGordanRecouplingEquiv.
invRecouplingHom agrees with coordinate (i, j) of (clebschGordanRecouplingEquiv).symm.
Recoupling scalars, basis expansions, and channel orthogonality #
Scalar recoupling coefficient from left channel (i, j) to right channel (r, s).
Instances For
Definitional Schur-scalar formula for recouplingCoeff.
Inverse scalar recoupling coefficient from right channel (r, s) to left channel (i, j).
Instances For
Definitional Schur-scalar formula for invRecouplingCoeff.
Congruence of recouplingCoeff along equality of underlying natural-number indices.
Congruence of invRecouplingCoeff along equality of underlying natural-number indices.
recouplingCoeff vanishes when the left and right channels have distinct total weights.
invRecouplingCoeff vanishes when the right and left channels have distinct total weights.
recouplingCoeff vanishes when the right outer coupling to k is inadmissible.
recouplingCoeff vanishes off the unique right outer index hmv.index for total weight k.
recouplingCoeff vanishes when the left outer coupling to k is inadmissible.
recouplingCoeff vanishes off the unique left outer index hup.index for total weight k.
invRecouplingCoeff vanishes when the left outer coupling to k is inadmissible.
invRecouplingCoeff vanishes off the unique left outer index hup.index for weight k.
recouplingHom acts on every ladder vector v_l by multiplication by recouplingCoeff.
invRecouplingHom acts on every ladder vector v_l by invRecouplingCoeff.
Action of clebschGordanRecouplingEquiv on every ladder vector v_l of a left channel.
Action of (clebschGordanRecouplingEquiv).symm on every v_l of a right channel.
Operator-level expansion of assoc composed with clebschGordanLeftInclusion.
Operator-level inverse expansion of assoc.symm composed with clebschGordanRightInclusion.
Triple-product recoupling expansion. Under BialgebraModule.assoc, every v_l of left
channel (i, j) expands in the right-channel v_l with coefficients recouplingCoeff.
Inverse triple-product recoupling expansion. Under (BialgebraModule.assoc).symm, every
v_l of right channel (r, s) expands in the left-channel v_l via invRecouplingCoeff.
Channel-summed left orthogonality of invRecouplingCoeff and recouplingCoeff.
Channel-summed right orthogonality of recouplingCoeff and invRecouplingCoeff.