Section 12 pasting: switcheroo expansion #
Expansion identities and the left-front contraction bound: the counterpart of
MIPRE/Background/LIDT/MIPStarRE/LDT/Pasting/SwitcherooCompletion/Expansion.lean in the port of
planning/c6b-plan.md (milestone M11, section "Port conventions").
The vendored second bipartite state ฯbi : QuantumState (ฮน ร ฮน) is the symmetric model
S : SymModel ๐ K, in the vendored argument position; the slice family is an
IdxPolyFamily params ๐ and the auxiliary family M an IdxProjSubMeas (Fq params) Outcome ๐.
The contraction witness switcherooAggregateLeftFront_contraction places operators by
leftTensor (ฮนโ := ฮน) without a state in the vendored file; here it takes the model as an
explicit first argument (switcherooAggregateLeftFront_contraction S params family M q), as the
witnesses of Co/Pasting/SwitcherooContraction/Split.lean do. It computes the sum in the local
algebra ๐, where it is โ_g X_g with switcherooAggregateFourthTermX, and pushes the bound
switcherooAggregateFourthTerm_middle_sum_le_one through S.L by S.leftTensor_le_one, in
place of the vendored conjTranspose_opTensor and opTensor_mono_left with the identity on the
second factor. The two pointwise normalizations unfold the ordered and reversed product families
by change and merge the placements by S.leftTensor_conjTranspose and
S.leftTensor_mul_leftTensor; the averaged expansion is switcherooAggregate_qSDDOp_expand
followed by avgOver_add and avgOver_sub, the four averages being the four terms by
definitional equality.
Not ported #
Nothing: every declaration of the vendored file is ported here.
References #
In LionSR/MIPStarRE at commit 507e8122, not in this repository:
references/ldt-paper/ld-pasting.tex
Contraction witness for the final sqrt chi left-front overlap step.
Normalize the pointwise self-product in the final switcheroo left-front
step to the split-by-g scalar.
Normalize the pointwise mixed product in the final switcheroo left-front step into the left-front scalar form.
Average the single-question four-term qSDDOp expansion over the
slice-pair distribution.