Actual torus and native-coordinate averages #
The integer covering is treated as an actual surjective additive homomorphism of the compact torus. Haar invariance is a conclusion, not an assumption.
Concentration of actual pulse covariance columns #
We use r = sqrt L, so that a slot has length r^2. Pointwise Gaussian
bounds on the fundamental component and an actual compactly supported cutoff
give mass of order r and first centered moment of order r^2. Division by
the mass then gives a direction error of order 1/r.
Smooth positive covariance solves #
For an actual real two-by-two matrix and target, the signed areas in Cramer's rule give an explicit strict cone. On that cone, the inverse solution and its positive square roots depend smoothly on smooth input data. A compact family has a uniform positive lower bound and a uniform tolerance for perturbing both the matrix and the target.
No assertion here supplies smoothness or error estimates for the manuscript's integrated columns. No assertion concerns extension through a zero-amplitude edge, where the strict cone hypotheses fail.
Two signed covariance slots #
The finite-dimensional algebra underlying Lemma 8.7 and equation (29) of the
candidate manuscript. In the orthonormal (N,K) coordinates, the two normalized
columns are (-a,-b) and (-a,b), with positive column scales. A target (-m,t)
lies strictly between them precisely when |a*t| < b*m.
The actual integrated columns in the manuscript include approximation errors. This file does not identify those columns with the exact model, or prove the Gaussian, parameter-derivative, or flat-edge estimates.
The two columns, with their individual positive size factors.
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Explicit squared amplitudes for the two signed slots.
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The explicit coefficients solve the two covariance equations exactly.
Thus the explicit formula is the matrix inverse applied to the stress.
The primary velocity amplitudes are positive square roots of the solve.
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- NavierStokes.Covariance.amplitudes a b scaleMinus scalePlus m t i = √(NavierStokes.Covariance.coefficients a b scaleMinus scalePlus m t i)
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Squared positive velocity amplitudes reproduce the exact model covariance.
The square-root viscosity factor and any common partition mask in (29)
produce precisely the expected factor ε * mask^2 in covariance.
The exact signed-slot model has positive primary amplitudes under the ratio condition stated in Section 8.3. This asserts no analytic error bound.
Vec2: an abbreviation for Fin 2 → ℝ /- The entrywise sup norm makes all metric assertions below unambiguous. -/.
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Cache the standard NormedAddCommGroup Mat2 instance to shorten typeclass synthesis.
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- One or more equations did not get rendered due to their size.
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Cache the standard NormedSpace ℝ Mat2 instance to shorten typeclass synthesis.
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- NavierStokes.SmoothCovariance.instSmoothCovariance2 = { toModule := Matrix.module, norm_smul_le := NavierStokes.SmoothCovariance.instSmoothCovariance2._proof_1 }
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Cramer's explicit formula, including Lean's total division convention.
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Both target-column oriented areas have the same nonzero orientation as the two original columns. The definition uses only polynomial inequalities.
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Agreement with the earlier exact signed-column formula.
Smoothness requires a nonvanishing determinant, independently of positivity.
Positive square-root amplitudes are smooth on the strict cone.
The complete amplitude vector, not only its coordinates, is smooth.
Smooth dependence of the coefficients as named in the original exact signed-slot module. All six scalar input functions are genuinely smooth.
Compactness supplies an actual common lower bound for the determinant magnitude and both solution coordinates, including an empty parameter set.
The same compact family keeps every positive amplitude uniformly away from zero; no claim is made for a family touching a zero-stress edge.
The strict area inequalities define an open set of matrix-target pairs.
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The solution map itself is C-infinity on the open set of admissible matrix-target data, without a prechosen parameterization.
The positive square-root solution is C-infinity on that same open set.
A single positive perturbation radius works for every datum in a compact subset of the strict cone. The perturbed data may be arbitrary actual matrices.
Uniform perturbation stability for a continuous family on a compact parameter set. Competing matrices need not form a continuous family.
Covariance amplitudes across an exponential-flat edge #
The normalized matrix and target are actual smooth functions with an explicit
strict cone. Columns are then multiplied by edge κᵢ, and the target by
edge σ. Exact inverse and square-root identities exhibit a positive remaining
exponential whenever κᵢ < σ; in particular the squared-factor convention
κᵢ = 2 λᵢ is covered by λᵢ < σ / 2.
The coefficient quotients are proved smooth from these formulas. Their smoothness across the singular matrix at the edge is not assumed.
Multiplication of column j by its scalar factor c j.
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- NavierStokes.FlatCovariance.columns G c i j = c j * G i j
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Scaled target, defined pointwise by r * T i.
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- NavierStokes.FlatCovariance.scaledTarget r T i = r * T i
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The actual edge-degenerate covariance matrix.
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- NavierStokes.FlatCovariance.edgeMatrix κ G x = NavierStokes.FlatCovariance.columns (G x) fun (j : Fin 2) => NavierStokes.FlatCutoff.edge (κ j) x
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Edge target, given by scaledTarget (edge σ x) (T x).
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The actual matrix-inverse solve, also defined at the zero edge.
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Primary amplitude, defined pointwise by Real.sqrt (inverseCoefficients σ κ G T x i).
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- NavierStokes.FlatCovariance.primaryAmplitude σ κ G T x i = √(NavierStokes.FlatCovariance.inverseCoefficients σ κ G T x i)
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The signed covariance update divides by the fixed positive primary.
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- NavierStokes.FlatCovariance.signedAmplitude σ τ κ G T R x i = NavierStokes.FlatCovariance.inverseCoefficients τ κ G R x i / (2 * NavierStokes.FlatCovariance.primaryAmplitude σ κ G T x i)
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Cramer's formula records the exact effect of individual column factors.
Exact cancellation of the column exponential in the actual inverse. This identity includes the edge and the full zero half-line.
Taking the square root halves the remaining exponential exponent.
The signed update retains the explicitly computed exponential margin;
the target R may have either sign.
Exact linearity in a scalar target factor, with no regularity or nonvanishing assumption on that factor.
The inverse still reconstructs its target at every real point, including the zero half-line where the matrix itself is singular.
Exact two-sided cross covariance of the primary and signed increment.
Smooth inverse coefficients at the edge, proved by the surviving exponential factor even though the actual matrix degenerates there.
Every fixed inverse-power loss is absorbed by the concrete primary exponential, including at zero.
The normalized signed quotient is smooth because its denominator is proved strictly positive from the explicit normalized cone.
An actual signed-stress numerator with an inverse-power loss still gives a smooth signed amplitude. Smoothness of the singular quotient is a result.
When a fundamental column factor is edge λᵢ and covariance therefore
carries its square, the concrete condition is exactly λᵢ < σ / 2. A signed
stress with the same target envelope retains the same flat exponent.
The requested stricter half-exponent condition also suffices when the exponential appears directly in a covariance column, without a square.
Concrete compact-family lower bounds with the vanishing factors left explicit. In particular the primary square-root denominator is controlled.
Actual all-order flatness of the primary, also after every fixed inverse-power loss, obtained from the proved smooth zero extension.
Evaluation of the actual inverse amplitude at a smooth signed edge coordinate, with independent smooth parameters in the normalized data.
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- NavierStokes.FlatCovariance.parameterPrimary σ κ d G T z = NavierStokes.FlatCovariance.primaryAmplitude σ κ (fun (x : ℝ) => G z) (fun (x : ℝ) => T z) (d z)
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Parameter signed, given by signedAmplitude σ τ κ (fun _ => G z) (fun _ => T z) (fun _ => R z) (d z).
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- NavierStokes.FlatCovariance.parameterSigned σ τ κ d G T R z = NavierStokes.FlatCovariance.signedAmplitude σ τ κ (fun (x : ℝ) => G z) (fun (x : ℝ) => T z) (fun (x : ℝ) => R z) (d z)
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Joint smoothness in the edge coordinate and all additional parameters, after any fixed inverse power of the edge coordinate.
The reference ODE envelope already constructed in GaussianEnvelope
supplies the pointwise Gaussian hypotheses with constants independent of slot
length.
Mass, given by ∫ v : ℝ, weight ψ x v.
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- NavierStokes.PulseCovariance.mass ψ x = ∫ (v : ℝ), NavierStokes.PulseCovariance.weight ψ x v
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All assumptions concern actual pointwise functions on the slot. No integrated covariance bound is an input.
- cutoff_continuous : Continuous ψ
- component_continuous : Continuous x
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The cutoff conditions, separated from the ODE envelope for the adapter.
- continuous : Continuous ψ
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Direct adapter from the growing-mode comparison a P ≤ x ≤ A P and
two-sided Gaussian estimates on the actual reference envelope P.
The positive scalar prefactor has precisely the required reciprocal-square - root size when the column coefficient has reciprocal-slot-length size.
Averaged direction, given by (∫ v : ℝ, weight ψ x v * q v) / mass ψ x.
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- NavierStokes.PulseCovariance.averagedDirection ψ x q = (∫ (v : ℝ), NavierStokes.PulseCovariance.weight ψ x v * q v) / NavierStokes.PulseCovariance.mass ψ x
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Concentration constant, given by A ^ 2 * firstGaussianMoment (2 * b) / PulseBounds.lowerMassConstant a B.
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A pointwise directional error plus a pointwise linear drift gives an actual integrated error. The moment bounds used below are derived above, not assumed.
The ODE directional error E/L is smaller than the Gaussian concentration
error 1/sqrt L.
The square-root profile used in the actual tangent model is globally one-Lipschitz; smoothness of a normalized direction is not assumed here.
Coordinates in the fixed tangent frame (N,K) of h N - s K, where
h = c₀ sqrt(1+s²).
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Normalized column, defined pointwise by averagedDirection ψ x (fun v => t v i / x v).
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- NavierStokes.PulseCovariance.normalizedColumn ψ x t i = NavierStokes.PulseCovariance.averagedDirection ψ x fun (v : ℝ) => t v i / x v
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Exact factorization of the actual covariance integral into its positive mass and normalized direction.
Directional concentration for actual fundamental tangent components.
The sole tangent estimate assumed is the pointwise ODE approximation to
h(v)N-s(v)K, with affine s and the exact square-root profile h.
The ODE error may instead be supplied as E/S on a slot with L ≤ κ S.
This converts it to the preceding concentration estimate.
A single actual pulse. Every estimate in this record is pointwise; neither its covariance integral nor its average direction is assumed.
Cutoff of
TangentPulse, of typeℝ → ℝ.Component of
TangentPulse, of typeℝ → ℝ.Tangent of
TangentPulse, of typeℝ → Vec2.- bounds : PulseBounds r a A b B self.cutoff self.component
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Signed slopes, given by ![u, -u].
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Signed pulse pair: an abbreviation for (j : Fin 2) → TangentPulse r a A b B c₀ (signedSlopes u j) (signedSlopes u j) E.
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- One or more equations did not get rendered due to their size.
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Actual matrix, defined pointwise by actualColumn (ci j) (pulses j).cutoff (pulses j).component (pulses j).tangent i.
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- NavierStokes.PulseCovariance.actualMatrix pulses ci i j = NavierStokes.PulseCovariance.actualColumn (ci j) (pulses j).cutoff (pulses j).component (pulses j).tangent i
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Normalized matrix, defined pointwise by normalizedColumn (pulses j).cutoff (pulses j).component (pulses j).tangent i.
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- NavierStokes.PulseCovariance.normalizedMatrix pulses i j = NavierStokes.PulseCovariance.normalizedColumn (pulses j).cutoff (pulses j).component (pulses j).tangent i
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Column scales, defined pointwise by ci j * mass (pulses j).cutoff (pulses j).component.
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- NavierStokes.PulseCovariance.columnScales pulses ci j = ci j * NavierStokes.PulseCovariance.mass (pulses j).cutoff (pulses j).component
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Cache the standard NormedAddCommGroup Mat2 instance to shorten typeclass synthesis.
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- One or more equations did not get rendered due to their size.
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Cache the standard NormedSpace ℝ Mat2 instance to shorten typeclass synthesis.
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- NavierStokes.PulseCovariance.instPulseCovariance2 = { toModule := Matrix.module, norm_smul_le := NavierStokes.PulseCovariance.instPulseCovariance2._proof_1 }
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A uniform slot threshold for the actual signed pulse pair over a compact
strict-cone family. Its matrix approximation is a conclusion of the Gaussian
moment and pointwise tangent estimates in TangentPulse, not a hypothesis.
Scalar cone inequalities and continuity of the four scalar model data
suffice. Compactness supplies both the uniform cone tolerance and the uniform
bounds on c₀,u, hence one slot threshold for every actual pulse pair.
Quotient point, given by ((z.1 : UnitAddCircle), (z.2 : UnitAddCircle)).
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- NavierStokes.TorusAverages.quotientPoint z = (↑z.1, ↑z.2)
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The manuscript's real covering matrix [[3,1],[1,5]].
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Torus covering, bundling toFun, map_zero, map_add.
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- One or more equations did not get rendered due to their size.
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Surjectivity is explicit: choose real lifts and apply the inverse matrix
(1/14)[[5,-1],[-1,3]] before projecting to the torus.
Every covering power preserves the actual Haar integral. Continuity is already sufficient; no Fourier-decay premise or assumed average identity occurs.
Square average, given by ∫ y in (0 : ℝ)..1, ∫ x in (0 : ℝ)..1, f (x, y).
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Unit-square version for a genuine continuous unit-periodic complex field.
Real-valued form, with the same actual unit-square integral.
Lattice periodization and its actual integral #
Lattice point, given by ((k.1 : ℝ), (k.2 : ℝ)).
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- NavierStokes.TorusAverages.latticePoint k = (↑k.1, ↑k.2)
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Each translated half-open unit square is an injective coordinate chart for the quotient to the torus.
A concrete smallness criterion for the native parallelogram. The product
norm on Plane is the maximum norm, so ball 0 r is the open native square.
A positive injective native radius always exists; this proof supplies the
explicit radius 1 / (4 * (‖L‖ + 1)).
The AddAction Frequency Plane structure used in torus averages.
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- One or more equations did not get rendered due to their size.
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Fundamental square, given by Ico (0 : ℝ) 1 ×ˢ Ico (0 : ℝ) 1.
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The half-open unit square is proved to tile the plane, using integer floors.
The periodization is the actual sum over integer translates.
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A compactly supported field has only finitely many active translates on every bounded set. This supplies an actual local finite-sum formula.
On an injective slot, a periodization equals the one native copy present there. The result includes the case that the native value itself is zero.
Products of actual periodized fields have no cross-copy terms when both native fields are supported in the same injective slot.
The set-integral and iterated-integral descriptions of the unit-square average agree. Endpoint choices have zero Lebesgue measure.
Every integrable field, in particular a smooth compactly supported slot, has exactly its plane integral as the integral of its lattice periodization.
Native coordinates and the determinant prefactor #
A native field placed at center in the linear coordinate chart L.
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- NavierStokes.TorusAverages.nativeField L center f z = f (L.symm (z - center))
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Actual linear change of variables, including the absolute determinant.
The native compact-slot average is obtained from periodization and a Jacobian theorem, with no assumed averaging identity.
The linear map with the radial and longitudinal vectors as its columns.
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- NavierStokes.TorusAverages.slotLinearMap vr vt = (Matrix.toLin (Module.Basis.finTwoProd ℝ) (Module.Basis.finTwoProd ℝ)) !![vr.1, vt.1; vr.2, vt.2]
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The genuine nondegenerate native chart.
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Rescaling the transverse coordinate by ci.
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η = ci * v - r0, written as the field in the native (ξ,η) coordinates.
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The actual native-slot average after every integer covering power. The
transverse-coordinate Jacobian is positive ci, not an assumed model scale.
Separation of the actual longitudinal and transverse integrals.
The native covariance coefficient before angular averaging.
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The real-cosine factor in Lemma 8.7 #
The displayed native prefactor in Lemma 8.7, for actual periodized slot
coefficients and actual angular averages. The harmonic is the rounded integer
k*p, so its only required property here is nonzero integrality.
The same exact prefactor with the transverse integral restricted to the actual pulse interval, using the already verified compact pulse support.