The Schrödinger flow on ℂℙⁿ is Hamiltonian, with Hamiltonian -2 ⟨H⟩ #
TERM-SCOPE(Kahler) TERM-SCOPE(Hamiltonian) TERM-SCOPE(MomentMap) — this module uses
the restricted senses of these words; specs/TERMS.md records what is backed and what is not.
Category: 1-Mathlib (1-Mathlib-staging in its mathematics; it consumes the corpus's).
Matrix.schrodingerUnitary (the unitary exp(-itH)) and its derivative
Matrix.schrodingerUnitary_hasDerivAt as the flow whose generator it identifies.
Brick G13 of specs/generator-layer-scoping.md (with the G2, G3, G4, G16 and G19 corollaries): the U(n+1) moment map. For a Hermitian
H, the unitary flow p ↦ exp(-itH) • p on ℂℙⁿ — the corpus's projected Schrödinger flow — is
Hamiltonian for the Fubini–Study form, and its Hamiltonian is -2 ⟨H⟩, the expectation value
⟪z, Hz⟫ / ‖z‖² up to the form's convention. Brick G6 (the torus) is the diagonal case.
expectation H p = ⟪z, Hz⟫.re / ‖z‖²— the expectation value on rays (expectation_mk,continuous_expectation);schrodingerHamiltonian H = -2 • expectation H;insertZeroCLM i— the tangent lift of the affine chart (0in sloti), anℝ-linear map;insertOne i w = insertOne i 0 + insertZeroCLM i w, sohasFDerivAt_insertOne; and the lift preserves the inner products the model form is written in (inner_insertZeroCLM_insertZeroCLM,inner_insertZeroCLM_insertOne,norm_sq_insertOne_toLpCLM);schrodingerChartField H i w— the velocity in charti,-i ((Hv)_{sⱼ} - (Hv)_i wⱼ)forv = insertOne i w; ★hasDerivAt_chartFun_schrodingerUnitary— it is the velocity of the flow: thet-derivative at0oft ↦ chartFun i (exp(-itH) • chartInv i w);schrodingerChartHam,hasFDerivAt_schrodingerChartHam— the chart Hamiltonian-2 ⟪v, Hv⟫.re / ‖v‖²and its derivative, throughHasFDerivAt.inneralong the affine lift;- ★★
fsModelForm_schrodingerChartField— the chart identityω_w (X_w, u) = dH_w u, proved in the ambient inner product: the lifted velocity is-i (Hv - (Hv)_i v), the(Hv)_iterms cancel, and what remains is the symmetry ofHandIm (i z) = Re z; - ★★★
schrodingerField_isHamiltonianVectorField—IsHamiltonianVectorField fsForm (schrodingerField H) (schrodingerHamiltonian H): the Schrödinger flow onℂℙⁿis Hamiltonian for the Fubini–Study form, with-2 ⟨H⟩as its Hamiltonian; schrodingerChartField_neg_diagonal,schrodingerHamiltonian_neg_diagonal— forH = -diag θthe field and the Hamiltonian are G6'storusChartFieldandtorusHamiltonian: the torus is the diagonal case;torusField_eq_hamiltonianVectorField,schrodingerField_eq_hamiltonianVectorField— both fields are the Hamiltonian vector fields(ω♭)⁻¹ dHof their Hamiltonians for the symplectic formfsForm(G2's existence-and-uniqueness construction,IsSymplectic.hamiltonianVectorField);contDiff_schrodingerChartHam, ★contMDiff_schrodingerHamiltonian, ★contMDiff_torusHamiltonian(both Hamiltonians areC^monℂℙⁿfor every orderm, soC^∞and real-analytic at once — one statement each since 2026-09-16), and ★★contMDiff_schrodingerField, ★★contMDiff_torusField— both fields areC^∞vector fields,C^∞sections of the tangent bundle, by G2's identification and G3's smoothness theorem;exists_isMIntegralCurveAt_schrodingerField,isMIntegralCurve_schrodingerField_eq, ★★expectation_eq_of_isMIntegralCurve_schrodingerField(⟨H⟩is conserved along every integral curve of the field), ★★★isMIntegralCurve_schrodingerUnitary_smul— the Schrödinger flowt ↦ exp(-itH) • pis the integral curve of its field, for everyp— and ★★expectation_schrodingerUnitary_smul(⟨H⟩is conserved by the flow), all G4;- G16 (2026-09-10). Given ★★★
isMIntegralCurve_torusUnitary_smul— the torus orbitt ↦ diag(e^{itθ}) • pis the integral curve oftorusField θ— which lives with the field inProjectiveSpaceMomentMap.leansince 2026-09-16 (it uses only the moment-map module's ownhasDerivAt_chartFun_torusUnitaryand group lawtorusUnitary_add_smul):isMIntegralCurve_torusField_eq, ★★eq_torusUnitary_smul_of_isMIntegralCurve(every integral curve throughpat0IS the orbit); ★★torusHamiltonian_eq_of_isMIntegralCurve_torusFieldand ★★torusHamiltonian_torusUnitary_smul(2 ∑ θₖ μₖis conserved along the curves and by the flow); - G19 (2026-09-10). ★★
contMDiff_omega_schrodingerField, ★★contMDiff_omega_torusField— both fields are analytic vector fields,C^ωsections of the tangent bundle: the Hamiltonian vector fields ofC^ωenergies for theC^ωformfsFormAnalytic(G12), by G19'scontMDiff_omega_hamiltonianVectorField; - Q29(e) (2026-09-12). ★★
hamiltonianFlow_schrodingerHamiltonian, ★★hamiltonianFlow_torusHamiltonian— the Schrödinger flow and the torus flow ARE the Hamiltonian flowsIsSymplectic.hamiltonianFlow(HamiltonianFlowVolume.lean) of-2⟨H⟩and of2 ∑ θₖ μₖ: the manifold flow of the Hamiltonian vector field isp ↦ exp(-itH) • p, by uniqueness of integral curves (integralFlow_eq_of_isMIntegralCurve); hence ★★fsVolume_map_schrodingerUnitary_smul,fsVolumeNormalized_map_schrodingerUnitary_smul— Liouville for the Schrödinger flow from the Hamiltonian, a corollary of the manifold-level theoremfsVolume_map_hamiltonianFlow(Q29(d′)), not of unitary invariance.
Honest scope #
⚠️ The sign and the factor are conventions. fsChartForm carries the -4 of its potential,
which makes the generator of the torus 2 · momentMap (G6); the corpus's Schrödinger flow is
exp(-itH), so its Hamiltonian is -2 ⟨H⟩. Nothing here rescales either; the statement shows
both.
⚠️ The flow is consumed, not built. Matrix.schrodingerUnitary and its derivative come from
Analysis/Matrix/SchrodingerUnitary.lean, under the L2Operator matrix norm (the one under which
hasDerivAt_exp_smul_const synthesises); this module opens that scope and adds nothing to it.
⚠️ Two routes to Liouville, both in the corpus. fsVolume_map_torusUnitary_smul (G10) and
fsVolume_map_smul (W1 on the sectors) are unitary invariance; fsVolume_map_schrodingerUnitary_smul
here is the manifold-level flow theorem (Q29, formerly G5) applied through the identification of the
flows. They prove the same equation by independent arguments; the second is the one that generalises
to a non-unitary Hamiltonian flow.
⚠️ Posits untouched. Posit 1 asserts that the dynamics generates the pointer torus; this
module says which Hamiltonian a given unitary flow has, for every Hermitian H, and does not
touch what generates it.
References: specs/generator-layer-scoping.md (G13, G6); Instances/ProjectiveSpaceMomentMap.lean
(torusChartField, torusHamiltonian, torusField_isHamiltonianVectorField);
Geometry/Manifold/HamiltonianVectorField.lean (G1); Instances/ProjectiveSpaceFubiniStudyMass.lean
(fsModelForm_apply, toLpCLM_apply); Instances/ProjectiveSpaceUnitaryAction.lean
(chartFun_smul_chartInv); Analysis/Matrix/SchrodingerUnitary.lean (schrodingerUnitary,
expNegITH_unitary_group, schrodingerUnitary_hasDerivAt);
specs/TERMS.md (Hamiltonian, moment map); specs/POSITS.md (Posit 1); specs/future-work.md.
The expectation value, on rays #
The tangent lift of the affine chart #
Insert 0 in slot i, as an ℝ-linear map: the lift of chart tangent vectors.
Equations
- Projectivization.insertZeroCLM i = LinearMap.toContinuousLinearMap { toFun := fun (u : Fin n → ℂ) => WithLp.toLp 2 (i.insertNth 0 u), map_add' := ⋯, map_smul' := ⋯ }
Instances For
The velocity and the Hamiltonian in the chart #
The velocity of t ↦ exp(-itH) • p in chart i: -i ((Hv)_{sⱼ} - (Hv)_i wⱼ),
v = insertOne i w.
Equations
- Projectivization.schrodingerChartField H i w j = -Complex.I * (H.mulVec (Projectivization.insertOne i w).ofLp (i.succAbove j) - H.mulVec (Projectivization.insertOne i w).ofLp i * w j)
Instances For
The lift of the chart velocity to the ambient space: -i (Hv - (Hv)_i v).
The derivative of the chart Hamiltonian, by the product and inverse rules from
HasFDerivAt.inner along the affine lift.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The chart identity ι_X ω = dH, in the ambient inner product #
★★ The chart identity: the Fubini–Study model form pairs the Schrödinger velocity with u
exactly as the derivative of the chart Hamiltonian does. Lifted to the ambient space, the velocity
is -i (Hv - (Hv)_i v); the (Hv)_i terms cancel, and what remains is Im (i z) = Re z together
with the symmetry of H.
The manifold statement #
The velocity field of the Schrödinger flow p ↦ exp(-itH) • p on ℂℙⁿ, read in the chart at
each point.
Equations
Instances For
★★★ The Schrödinger flow on ℂℙⁿ is Hamiltonian for the Fubini–Study form, with -2 ⟨H⟩
as its Hamiltonian: ι_X ω_FS = dH on the manifold, for every Hermitian H.
The field is the velocity of the flow #
★ The field is the velocity of the flow: at every chart point, schrodingerChartField is
the t-derivative at 0 of t ↦ exp(-itH) • p, read in the chart.
The torus is the diagonal case (G6) #
Both fields are THE Hamiltonian vector fields of their Hamiltonians (G2) #
The torus field is the Hamiltonian vector field (ω♭)⁻¹ dH of torusHamiltonian θ for the
symplectic form fsForm (G2 + G6).
The Schrödinger field is the Hamiltonian vector field (ω♭)⁻¹ dH of -2 ⟨H⟩ for the
symplectic form fsForm (G2 + G13).
The Hamiltonians are C^m for every order m (so C^∞ and C^ω), and both fields are #
C^∞ vector fields (G3)
The chart Hamiltonian is C^m for every order m (∞ and ω included): inner-product
calculus along the affine lift, every step generic in the order.
★ The Hamiltonian of the Schrödinger flow is C^m on ℂℙⁿ for every order m (C^∞ and
real-analytic in particular).
★ The Hamiltonian of the torus action is C^m on ℂℙⁿ for every order m (the diagonal
case).
★★ The Schrödinger vector field on ℂℙⁿ is a C^m vector field for every infinite order
m (∞ and ω): it is the Hamiltonian vector field of a C^m energy for the C^ω form
fsForm
(G2), and those are C^m (G3, contMDiff_hamiltonianVectorField_of_contMDiff).
★★ The Schrödinger vector field on ℂℙⁿ is a C^∞ vector field (a C^∞ section of the
tangent bundle).
★★ The torus vector field on ℂℙⁿ is a C^m vector field for every infinite order m.
★★ The torus vector field on ℂℙⁿ is a C^∞ vector field.
Integral curves on ℂℙⁿ: the Schrödinger flow is one, and ⟨H⟩ is conserved (G4) #
Local existence of integral curves of the Schrödinger field, through every point.
Uniqueness of global integral curves of the Schrödinger field.
★★ ⟨H⟩ is conserved along every integral curve of the Schrödinger field.
★★★ The Schrödinger flow is the integral curve of its field: t ↦ exp(-itH) • p is a
global integral curve of schrodingerField H, for every p. In the chart at exp(-itH) • p the
curve is s ↦ chartFun (exp(-i(s-t)H) • q), whose derivative at s = t is the chart velocity
(hasDerivAt_chartFun_schrodingerUnitary, shifted by the group law expNegITH_unitary_group).
★★ ⟨H⟩ is conserved by the Schrödinger flow: ⟨H⟩_{exp(-itH) • p} = ⟨H⟩_p.
The torus orbits are integral curves of the torus field (G16) #
continuous_torusUnitary_smul and isMIntegralCurve_torusUnitary_smul moved to
ProjectiveSpaceMomentMap.lean on 2026-09-16 (they use nothing from this file, and the
moment-map module's docstring cites them); the uniqueness corollaries stay here.
Uniqueness of global integral curves of the torus field.
★★ The torus orbit is THE integral curve: every global integral curve of the torus field
through p at time 0 is t ↦ diag(e^{itθ}) • p.
★★ The torus Hamiltonian 2 ∑ θₖ μₖ is conserved along every integral curve of the torus
field.
★★ The torus Hamiltonian is conserved by the torus flow:
2 ∑ θₖ μₖ (diag(e^{itθ}) • p) = 2 ∑ θₖ μₖ (p).
Both fields are analytic (G19) #
The ω case of contMDiff_schrodingerField_of_le / contMDiff_torusField_of_le: one proof with
the C^∞ case since 2026-09-17.
★★ The Schrödinger vector field on ℂℙⁿ is an analytic vector field.
★★ The torus vector field on ℂℙⁿ is an analytic vector field.
The flows are the Hamiltonian flows, and Liouville from the Hamiltonian (Q29(e)) #
★★ The Schrödinger flow IS the Hamiltonian flow of -2⟨H⟩: for Hermitian H, the manifold
flow of the Hamiltonian vector field of schrodingerHamiltonian H is p ↦ exp(-itH) • p, by
uniqueness of integral curves.
★★ The torus flow IS the Hamiltonian flow of 2 ∑ θₖ μₖ: the manifold flow of the
Hamiltonian vector field of torusHamiltonian θ is p ↦ diag(e^{itθ}) • p.
★★ Liouville for the Schrödinger flow, from the Hamiltonian: p ↦ exp(-itH) • p preserves
the Fubini–Study volume because it is the Hamiltonian flow of -2⟨H⟩
(fsVolume_map_hamiltonianFlow), not because it is unitary (fsVolume_map_smul).
The same for the normalised volume, fsMeasure p₀.