lattice-system

Legacy long-form records: Spin foundations and Tasaki Chapter 2, part 2

Interim authority. These records contain long statement and implementation-history cells moved from the legacy catalogue tables for readability. Each record is linked exactly once from its original table position.

Interim catalogue

Record from former line 1978

Lean name: tasaki23_lowered_ne_zero_of_marshall_pos / totalSpinSOpMinus_mulVec_magSectorEmbedding_apply_eq_site_sum / tasaki23_lowered_marshall_pos_of_site_sum_pos / tasaki23_lowering_identifies_adjacent_sector_energy / tasaki23_lowering_identifies_adjacent_sector_energy_with_nonzero / tasaki23_lowering_identifies_adjacent_sector_energy_of_site_sum_pos

File: Not recorded in the former two-column table

Statement and implementation chronicle:

Tasaki §2.5 Theorem 2.3 adjacent-sector energy identification, conditional lowering step with non-vanishing and site-sum positivity form: if an embedded magSumS = M source-sector eigenvector has eigenvalue μ, and its lowered vector Ŝ^-_tot Ψ_M satisfies the Marshall-positive hypothesis in the adjacent sector M + 1, then strict positivity already implies Ŝ^-_tot Ψ_M ≠ 0, and the full-Hilbert-space Theorem 2.2 uniqueness clause in sector M + 1 identifies the target sector eigenvalue with μ. The lowered component is also expanded as a sum of the single-site lowering contributions ∑ x, Ŝ^-_x Ψ_M;

therefore the same package can be invoked from the local site-sum strict positivity hypothesis. This combines non-vanishing from strict Marshall positivity, ladder eigenvalue preservation, the sector-support shift, and the #869 target-sector uniqueness theorem;

the remaining critical-path input is to prove the sitewise Marshall-positivity hypothesis for the lowered vector. Tasaki, Springer 2020, §2.5 Theorem 2.3, p. 42 (file Quantum/SpinS/Theorem23Local.lean for the two surviving subjects tasaki23_lowered_ne_zero_of_marshall_pos and totalSpinSOpMinus_mulVec_magSectorEmbedding_apply_eq_site_sum;

tasaki23_lowered_marshall_pos_of_site_sum_pos lived in Quantum/SpinS/Theorem23LocalDifferenceMarshall.lean, tasaki23_lowering_identifies_adjacent_sector_energy and tasaki23_lowering_identifies_adjacent_sector_energy_with_nonzero lived in Quantum/SpinS/Theorem23LocalDifferenceEnergy.lean, and tasaki23_lowering_identifies_adjacent_sector_energy_of_site_sum_pos lived in Quantum/SpinS/Theorem23LocalDifferenceEnergyCasimir.lean, all three deleted in PR #3919 (bulk orphan-module deletion))

Record from former line 1986

Lean name: heisenbergHamiltonianS_mulVec_totalSpinSOpMinus_pow_of_eigenvec / heisenbergHamiltonianS_mulVec_totalSpinSOpPlus_pow_of_eigenvec / totalSpinSOpMinus_pow_mulVec_mem_magSubspaceS_of_mem / totalSpinSOpPlus_pow_mulVec_mem_magSubspaceS_of_mem / tasaki23OutsideGroundLeftIteratedLadderFullReachCallback / tasaki23OutsideGroundRightIteratedLadderFullReachCallback / tasaki23OutsideGroundAdmissibleFullReachCallback_of_iterated_ladder_callbacks / tasaki23OutsideGroundEnergyLowerFamilyCallback_of_iterated_ladder_full_reach / tasaki_2_5_theorem_2_3_of_threaded_predictedGS_of_unpacked_reembedded_real_source_weight_predecessor_difference_pos_of_iterated_ladder_full_reach_discharge_nonempty

File: Not recorded in the former two-column table

Statement and implementation chronicle:

Outside-ground iterated total-spin ladder reach for Tasaki §2.5 Theorem 2.3: the outside reach input is reduced from an arbitrary full-space reached eigenvector to non-zeroness of an iterated total-spin ladder output. The Lean bridge proves that (Ŝ^-_tot)^k and (Ŝ^+_tot)^k preserve the Heisenberg eigenvalue and shift magSubspaceS by exactly -k and +k;

the left and right callbacks therefore only have to choose an admissible target sector and show that the corresponding iterated ladder vector is nonzero. The resulting full-space admissible-reach callback feeds the lower-family bridge, and the discharged final boundary passes that lower family directly to the source common-energy final boundary. Tasaki, Springer 2020, §2.5 Theorem 2.3, p. 42;

Seneta, Non-negative Matrices and Markov Chains, 3rd ed., Springer 2006, §1.2, pp. 27–28 (file Quantum/SpinS/Theorem23Local.lean for the four surviving ladder-power lemmas;

tasaki23OutsideGroundLeftIteratedLadderFullReachCallback, tasaki23OutsideGroundRightIteratedLadderFullReachCallback, tasaki23OutsideGroundAdmissibleFullReachCallback_of_iterated_ladder_callbacks and tasaki23OutsideGroundEnergyLowerFamilyCallback_of_iterated_ladder_full_reach lived in Quantum/SpinS/Theorem23OutsideGround.lean, and the wrapper tasaki_2_5_theorem_2_3_of_threaded_predictedGS_of_unpacked_reembedded_real_source_weight_predecessor_difference_pos_of_iterated_ladder_full_reach_discharge_nonempty lived in Quantum/SpinS/Theorem23Final.lean, both deleted in PR #3645 (unsound saturated-ladder Theorem 2.3 route))