lattice-system

Legacy catalogue: Gibbs state (Tasaki §3.3)

Interim authority. This lossless catalogue chunk remains authoritative for formalization status and capstone identification until Issue #5228. The version 1 JSON catalogue is still a non-authoritative prototype.

Interim catalogueSpin models, Chapters 3–7, and spectral tools

Gibbs state (Tasaki §3.3)

Primary reference: Tasaki, Physics and Mathematics of Quantum Many-Body Systems, §3.3.

All theorems in this module are fully proved with zero sorry.

Lean name Statement File
gibbsExp β H exp(-βH) := Matrix.exp (-β • H) Quantum/GibbsState.lean
gibbsExp_isHermitian exp(-βH) is Hermitian (when H is Hermitian) Quantum/GibbsState.lean
gibbsExp_zero exp(-0·H) = 1 (Tasaki §3.3, pp. 75–78) Quantum/GibbsState.lean
gibbsExp_add exp(-(β₁+β₂)H) = exp(-β₁H) · exp(-β₂H) (one-parameter group) Quantum/GibbsState.lean
gibbsExp_add_of_commute_hamiltonians exp(-β(H₁+H₂)) = exp(-βH₁) · exp(-βH₂) for commuting H₁, H₂ Quantum/GibbsState.lean
gibbsExp_neg_mul_self exp(βH) · exp(-βH) = 1 Quantum/GibbsState.lean
gibbsExp_self_mul_neg exp(-βH) · exp(βH) = 1 Quantum/GibbsState.lean
gibbsExp_isUnit exp(-βH) is invertible Quantum/GibbsState.lean
gibbsExp_ne_zero exp(-βH) ≠ 0 (corollary of gibbsExp_isUnit) Quantum/GibbsState.lean
gibbsState_ne_zero ρ_β ≠ 0 when Z(β) ≠ 0 Quantum/GibbsState.lean
gibbsState_inv (ρ_β)⁻¹ = Z(β) · e^{βH} when Z(β) ≠ 0 (general matrix inverse, generalises gibbsState_zero_inv) Quantum/GibbsState.lean
partitionFn_smul_gibbsState_eq_gibbsExp Z(β) · ρ_β = e^{-βH} when Z(β) ≠ 0 (canonical rescaled identity) Quantum/GibbsState.lean
partitionFn_mul_gibbsExpectation_eq Z(β) · ⟨A⟩_β = Tr(e^{-βH} · A) when Z(β) ≠ 0 (canonical unnormalised expectation) Quantum/GibbsState.lean
gibbsExp_natCast_mul exp(-(n·β)H) = (exp(-βH))^n for n : ℕ (exact discrete semigroup identity) Quantum/GibbsState.lean
gibbsExp_two_mul exp(-(2β)H) = exp(-βH) · exp(-βH) Quantum/GibbsState.lean
gibbsExp_inv (exp(-βH))⁻¹ = exp(βH) (matrix inverse made explicit) Quantum/GibbsState.lean
gibbsExp_intCast_mul exp(-(n·β)H) = (exp(-βH))^n for n : ℤ (integer-power extension) Quantum/GibbsState.lean
partitionFn β H Z := Matrix.trace (exp(-βH)) Quantum/GibbsState.lean
partitionFn_zero Z(0) = Fintype.card (Λ → Fin 2) (dimension of the Hilbert space) Quantum/GibbsState.lean
partitionFn_zero_ne_zero Z(0) ≠ 0 (concrete sorry-free proof that the partition function is nonzero at β = 0) Quantum/GibbsState.lean
Matrix.IsHermitian.trace_im for any Hermitian A : Matrix n n ℂ, A.trace.im = 0 (generic helper; relocated to the matrix-analysis layer in PR #4344) Math/MatrixAnalysis/HermitianTrace.lean
partitionFn_im_of_isHermitian for Hermitian H, (partitionFn β H).im = 0 (Z is real) Quantum/GibbsState.lean
gibbsState_mul_self_trace Tr(ρ_β²) = Z(2β) / Z(β)² (purity / Rényi-2 entropy precursor) Quantum/GibbsState.lean
gibbsState_pow_trace Tr(ρ_β^n) = Z(nβ) / Z(β)^n for any n : ℕ (Rényi-n entropy precursor) Quantum/GibbsState.lean
gibbsState_zero ρ_0 = (1/dim) · I (maximally mixed state at infinite temperature) Quantum/GibbsState.lean
gibbsState_zero_inv ρ_0⁻¹ = dim · I (matrix inverse at β = 0) Quantum/GibbsState.lean
gibbsExpectation_zero ⟨A⟩_0 = (1/dim) · Tr A (high-temperature limit) Quantum/GibbsState.lean
gibbsState β H ρ := (1/Z) • exp(-βH) Quantum/GibbsState.lean
gibbsState_trace Tr(ρ) = 1 Quantum/GibbsState.lean
gibbsState_isHermitian ρ is Hermitian Quantum/GibbsState.lean
gibbsExpectation β H O ⟨O⟩ := Matrix.trace (ρ * O) Quantum/GibbsState.lean
gibbsExpectation_one ⟨1⟩ = 1 Quantum/GibbsState.lean
gibbsExpectation_add ⟨O₁ + O₂⟩ = ⟨O₁⟩ + ⟨O₂⟩ (linearity in observable) Quantum/GibbsState.lean
gibbsExpectation_smul ⟨c · O⟩ = c · ⟨O⟩ (scalar linearity, c : ℂ) Quantum/GibbsState.lean
gibbsExpectation_neg ⟨-O⟩ = -⟨O⟩ Quantum/GibbsState.lean
gibbsExpectation_sub ⟨A - B⟩ = ⟨A⟩ - ⟨B⟩ Quantum/GibbsState.lean
gibbsExpectation_sum ⟨∑ i ∈ s, f i⟩ = ∑ i ∈ s, ⟨f i⟩ (finite-sum linearity) Quantum/GibbsState.lean
gibbsExp_commute_hamiltonian [exp(-βH), H] = 0 (Tasaki §3.3, p. 80) Quantum/GibbsState.lean
gibbsState_commute_hamiltonian [ρ_β, H] = 0, i.e. ρ_β is stationary under the dynamics generated by H (Tasaki §3.3, p. 80) Quantum/GibbsState.lean
Matrix.trace_mul_star_of_isHermitian star (Tr(A · B)) = Tr(A · B) for Hermitian A, B : Matrix n n ℂ (algebraic core, Gibbs-independent; relocated to the matrix-analysis layer in PR #4344) Math/MatrixAnalysis/HermitianTrace.lean
gibbsExpectation_star_of_isHermitian star ⟨O⟩_β = ⟨O⟩_β for Hermitian H, O Quantum/GibbsState.lean
gibbsExpectation_im_of_isHermitian (⟨O⟩_β).im = 0 for Hermitian H, O Quantum/GibbsState.lean
gibbsExpectation_ofReal_re_eq_of_isHermitian ((⟨O⟩_β).re : ℂ) = ⟨O⟩_β for Hermitian H, O (real-cast equality) Quantum/GibbsState.lean
gibbsExpectation_mul_hamiltonian_comm ⟨H · A⟩_β = ⟨A · H⟩_β for any A (Tasaki §3.3, p. 80) Quantum/GibbsState.lean
gibbsExpectation_mul_comm_of_commute_hamiltonian for any conserved A ([A, H] = 0), ⟨A · O⟩_β = ⟨O · A⟩_β Quantum/GibbsState.lean
gibbsExpectation_commutator_eq_zero_of_commute_hamiltonian for any conserved A, ⟨A · O − O · A⟩_β = 0 (selection rule) Quantum/GibbsState.lean
gibbsExpectation_commutator_hamiltonian ⟨[H, A]⟩_β = 0 (conservation law) Quantum/GibbsState.lean
gibbsExpectation_hamiltonian_im (⟨H⟩_β).im = 0 for Hermitian H (real energy expectation) Quantum/GibbsState.lean
gibbsExpectation_sq_im_of_isHermitian (⟨O · O⟩_β).im = 0 for Hermitian H, O (second-moment realness, variance precursor) Quantum/GibbsState.lean
gibbsExpectation_pow_im_of_isHermitian (⟨O^n⟩_β).im = 0 for Hermitian H, O, any n : ℕ (all natural-power moments real) Quantum/GibbsState.lean
gibbsVariance β H O Var_β(O) := ⟨O · O⟩_β − ⟨O⟩_β² (canonical-ensemble variance) Quantum/GibbsState.lean
gibbsVariance_eq unfolding lemma for gibbsVariance Quantum/GibbsState/Covariance.lean
gibbsVariance_im_of_isHermitian (Var_β(O)).im = 0 for Hermitian H, O (variance is real) Quantum/GibbsState/Covariance.lean
gibbsVariance_zero at β = 0, Var_0(O) = (1/dim) · Tr(O²) − ((1/dim) · Tr O)² Quantum/GibbsState/Covariance.lean
gibbsVariance_eq_centered_sq Var_β(O) = ⟨(O − ⟨O⟩_β · 1) · (O − ⟨O⟩_β · 1)⟩_β (centered-square form, Z ≠ 0) Quantum/GibbsState/Covariance.lean
gibbsCovariance β H A B Cov_β(A, B) := ⟨A · B⟩_β − ⟨A⟩_β · ⟨B⟩_β (canonical-ensemble complex covariance) Quantum/GibbsState.lean
gibbsCovariance_eq unfolding lemma for gibbsCovariance Quantum/GibbsState/Covariance.lean
gibbsCovariance_self_eq_variance Cov_β(O, O) = Var_β(O) Quantum/GibbsState/Covariance.lean
gibbsCovariance_sub_swap_eq_commutator Cov_β(A, B) − Cov_β(B, A) = ⟨A · B − B · A⟩_β (antisymmetric part = commutator expectation) Quantum/GibbsState/Covariance.lean
gibbsCovariance_add_left Cov_β(A₁ + A₂, B) = Cov_β(A₁, B) + Cov_β(A₂, B) Quantum/GibbsState/Covariance.lean
gibbsCovariance_add_right Cov_β(A, B₁ + B₂) = Cov_β(A, B₁) + Cov_β(A, B₂) Quantum/GibbsState/Covariance.lean
gibbsCovariance_smul_left Cov_β(c • A, B) = c · Cov_β(A, B) Quantum/GibbsState/Covariance.lean
gibbsCovariance_smul_right Cov_β(A, c • B) = c · Cov_β(A, B) Quantum/GibbsState/Covariance.lean
gibbsCovariance_const_smul_one_{left,right}_eq_zero Cov_β(c • 1, B) = 0 and Cov_β(A, c • 1) = 0 (when Z ≠ 0) Quantum/GibbsState.lean
gibbsCovarianceSymm_const_smul_one_{left,right}_eq_zero Cov^s_β(c • 1, B) = 0 and Cov^s_β(A, c • 1) = 0 (when Z ≠ 0) Quantum/GibbsState.lean
gibbsCovarianceSymm β H A B Cov^s_β(A, B) := (1/2) · ⟨A · B + B · A⟩_β − ⟨A⟩_β · ⟨B⟩_β (symmetric / real-valued covariance) Quantum/GibbsState.lean
gibbsCovarianceSymm_self_eq_variance Cov^s_β(O, O) = Var_β(O) Quantum/GibbsState/Covariance.lean
gibbsCovarianceSymm_im_of_isHermitian (Cov^s_β(A, B)).im = 0 for Hermitian H, A, B Quantum/GibbsState/Covariance.lean
gibbsCovarianceSymm_comm Cov^s_β(A, B) = Cov^s_β(B, A) (symmetric in observables) Quantum/GibbsState/Covariance.lean
gibbsCovarianceSymm_add_{left,right} additivity of Cov^s_β in each argument Quantum/GibbsState.lean
gibbsCovarianceSymm_smul_{left,right} scalar pull-out from each argument of Cov^s_β Quantum/GibbsState.lean
gibbsVariance_add Var_β(A + B) = Var_β(A) + Var_β(B) + 2 · Cov^s_β(A, B) (sum-of-observables variance identity) Quantum/GibbsState/Covariance.lean
gibbsVariance_one Var_β(1) = 0 (when Z ≠ 0) Quantum/GibbsState/Covariance.lean
gibbsVariance_smul Var_β(c • A) = c² · Var_β(A) Quantum/GibbsState/Covariance.lean
gibbsVariance_smul_one Var_β(c • 1) = 0 (when Z ≠ 0) Quantum/GibbsState/Covariance.lean
gibbsVariance_neg Var_β(−A) = Var_β(A) Quantum/GibbsState/Covariance.lean
gibbsVariance_add_const_smul_one Var_β(A + c • 1) = Var_β(A) (when Z ≠ 0) Quantum/GibbsState/Covariance.lean
gibbsCovariance_eq_symm_add_half_commutator Cov_β(A, B) = Cov^s_β(A, B) + (1/2) · ⟨A · B − B · A⟩_β (symmetric / antisymmetric decomposition) Quantum/GibbsState/Covariance.lean
gibbsCovarianceSymm_eq_half_add_swap Cov^s_β(A, B) = (1/2) · (Cov_β(A, B) + Cov_β(B, A)) Quantum/GibbsState/Covariance.lean
gibbsCovariance_eq_symm_of_commute for commuting A, B, Cov_β(A, B) = Cov^s_β(A, B) Quantum/GibbsState/Covariance.lean
Matrix.trace_mul_conjTranspose_swap_of_isHermitian star Tr(ρ · X) = Tr(ρ · Xᴴ) for Hermitian ρ (generic helper) Quantum/GibbsState.lean
gibbsExpectation_star_swap_of_isHermitian star ⟨A · B⟩_β = ⟨B · A⟩_β for Hermitian H, A, B Quantum/GibbsState/Covariance.lean
gibbsExpectation_anticommutator_im (⟨A·B + B·A⟩_β).im = 0 (anticommutator is real) Quantum/GibbsState/Covariance.lean
gibbsExpectation_commutator_re (⟨A·B − B·A⟩_β).re = 0 (commutator is purely imaginary) Quantum/GibbsState/Covariance.lean
gibbsExpectation_mul_hamiltonian_im (⟨H · O⟩_β).im = 0 for Hermitian H, O Quantum/GibbsState/Covariance.lean

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