The packet stage invariant #
GrowthData contains the Euler state, activation time and strain decomposition used to
prove gradient growth. Stage adds the source bounds and frame guards needed to construct
the next packet. Separating them lets the growth theorem apply without assuming the
successor construction's hypotheses. All cumulative bounds use only earlier indices.
The transverse packet data of a parent in the fixed reference plane: its
frame, inverse frame and strain along the centre trajectory, against which a
stage's ParentFrame is measured.
Equations
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The state, activation and strain bounds used by the growth argument. The common horizon and Sobolev realisation also support comparison with other Euler evolutions. These data impose no hypotheses on a successor packet.
- parent : EulerParentPacketFrames.Parent
The parent: the volume-preserving particle map, with its velocity and acceleration, that carries the current Euler state on
[0, parent.T]. Its frame, strain and curvature are the coefficients every estimate reads. - state : EulerParentPacketFrames.SmoothState self.parent
The current Euler solution on the parent: a pointwise classical
Evolution, its Sobolev realisationregularity(converted to an ordinary evolution by the contradiction), its label bounds, and its odd symmetry, which makes the strain at the origin equal to the velocity gradient there (strain_origin). - time : ℝ
The activation time of the most recently added packet (
0at the base stage). The divergent quantityactivationGradientis the velocity gradient at(time, 0). The activation time is a time of the stage solution.
Every stage horizon lies inside the base horizon, so all stage solutions can be compared with one hypothetical evolution on
[0, baseHorizon].- frame : EulerPacketSourceGeometry.ParentFrame (frameData self.parent) self.time
The leading rank-one part of the strain at the centre has shear
previousShear n, the target shear of the latest packet. This is the term the growth argument isolates.- frame_bound : self.frame.G ≤ EulerPacketLowConstants.frameConstant * (1 + EulerPacketSourceScaleSequence.olderShear S.J S.X n)
The background
Bis bounded one shear level lower, byframeConstant·(1 + olderShear n), so that the leading term dominates it. The remainder after
Band the rank-one shear are removed is at mostpriorError n, an inverse fourth root of the previous frequency, which is negligible against the leading shear.
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A full packet stage, including the induction hypotheses needed by the successor
construction. Stage.toGrowthData retains only the state, activation and frame bounds
needed for gradient growth. The full record keeps its original projection interface.
- parent : EulerParentPacketFrames.Parent
The parent: the volume-preserving particle map, with its velocity and acceleration, that carries the current Euler state on
[0, parent.T]. Its frame, strain and curvature are the coefficients every estimate reads. - state : EulerParentPacketFrames.SmoothState self.parent
The current Euler solution on the parent: a pointwise classical
Evolution, its Sobolev realisationregularity(converted to an ordinary evolution by the contradiction), its label bounds, and its odd symmetry, which makes the strain at the origin equal to the velocity gradient there (strain_origin). - low : EulerParentPacketFrames.LowBounds self.parent
The low-frequency source bounds of the parent: exterior and core lower bounds
Be,Bcon the initial strain, the curvature boundK, the localization lengthLand the core radiusr. They feed the coercivity guardsmallof the next parent. - time : ℝ
The activation time of the most recently added packet (
0at the base stage). The divergent quantityactivationGradientis the velocity gradient at(time, 0). The activation time is a time of the stage solution.
The base stage is activated at time
0; the forward step poses its packet there.After the first step the activation time is at least a twelfth of the base horizon. This bounds
time⁻¹, and through it the history terms of the joined step (history_layer).Every stage horizon lies inside the base horizon, so all stage solutions can be compared with one hypothetical evolution on
[0, baseHorizon].The parent's scale is
supportScale n: the next increment is supported in a ball of radius half this scale.- label_eq : self.state.labels.K = EulerPacketSourceScaleSequence.previousFrequency S.J S.D S.X n ^ 80
The label constant of the state (the Sobolev size of the parent's displacement, velocity and acceleration) is
previousFrequency n ^ 80; the next packet's frequency guard must dominate it. - gradient_bound (t : ↑(Set.Icc 0 self.parent.T)) (x : EulerSmoothLimit.Space) : ‖fderiv ℝ (fun (y : EulerSmoothLimit.Space) => self.state.evolution.velocity (↑t, y)) x‖ ≤ EulerPacketLowConstants.gradientConstant * EulerPacketSourceScaleSequence.previousShear S.J S.X n
The velocity gradient is bounded on the whole horizon by
gradientConstant·previousShear n: the upper bound matching the lower bound at the centre, consumed by the next step's low bounds and history data. - hessian_bound (t : ↑(Set.Icc 0 self.parent.T)) (x : EulerSmoothLimit.Space) : ‖fderiv ℝ (self.state.evolution.force t) x‖ ≤ EulerPacketLowConstants.hessianConstant * EulerPacketSourceScaleSequence.previousShear S.J S.X n * EulerPacketSourceScaleSequence.olderShear S.J S.X n
The pressure Hessian (the gradient of the force) is bounded by
hessianConstant·previousShear n·olderShear n. - exterior_bound : self.low.Be ≤ EulerBaseDatum.initialCoefficientCost + ∑ i ∈ Finset.range n, EulerPacketInductionScales.initialIncrement S.J S.X i
Cumulative bound on the exterior strain constant: the base cost plus the summable per-stage increments of the scale choice.
- core_bound : self.low.Bc ≤ EulerPacketLowConstants.gradientConstant * S.X ^ 1000 + ∑ i ∈ Finset.range n, EulerPacketInductionScales.initialIncrement S.J S.X i
Cumulative bound on the core strain constant, starting from the base shear
X^1000. - pressure_bound : self.low.K ≤ EulerBaseDatum.initialCoefficientCost + EulerBaseDatum.literalInitialPressureCost S.D S.X + ∑ i ∈ Finset.range n, EulerPacketInductionScales.pressureIncrement S.J S.X i
Cumulative bound on the curvature constant, starting from the base pressure cost. Together with the two bounds above it keeps the coercivity guard
smalltrue at every stage. The localization length is determined by the core bound.
The core radius is the base radius
X^(-1000)at every stage.- frame : EulerPacketSourceGeometry.ParentFrame (frameData self.parent) self.time
The leading rank-one part of the strain at the centre has shear
previousShear n, the target shear of the latest packet. This is the term the growth argument isolates.- frame_bound : self.frame.G ≤ EulerPacketLowConstants.frameConstant * (1 + EulerPacketSourceScaleSequence.olderShear S.J S.X n)
The background
Bis bounded one shear level lower, byframeConstant·(1 + olderShear n), so that the leading term dominates it. The remainder after
Band the rank-one shear are removed is at mostpriorError n, an inverse fourth root of the previous frequency, which is negligible against the leading shear.- coupling_error : |self.frame.a - 1| ≤ 2 * ∑ i ∈ Finset.range n, EulerParentRenewalScale.renewalCost S.J S.D 4 c EulerPacketLowConstants.frameConstant S.X i
The normalised coupling
a = ⟨m̂, B v̂⟩stays within a summable distance of1; each renewal moves it by at mostrenewalCost i. This gives1/2 ≤ a ≤ 2(coupling_bounds). - tilt_lower : 1 / 2 ≤ self.frame.sigma ^ 2 * EulerPacketSourceScaleChoice.scaleSequence S.J S.X n ^ 2
The normalised tilt
σ² = ⟨m̂ × v̂, B v̂⟩/ais at least1/(2 x_n²). The normalised tilt is at most
2/x_n²: the renewed frame is nearly untilted, at the scale of the sequence.- compression : n ≠ 0 → inner ℝ ((self.frame.B self.time) (EulerPacketNormalizedPrimary.unit (self.frame.m self.time))) (EulerPacketNormalizedPrimary.unit (self.frame.m self.time)) + EulerPacketSourceScaleActual.priorError S.J S.D S.X n < 0
After the first step the background strain compresses along the ray with a margin exceeding
priorError n. Sincem' = -Bᵀm, this makes‖m‖, and with it the shearc‖m‖‖v‖of the next packet, grow; the joined guards take it as input and the renewal re-establishes it.
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The positive post-activation time width puts activation inside the horizon.
The common base horizon bounds every activation time by one.
Forget the source bounds and frame guards that only the successor construction needs.
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- One or more equations did not get rendered due to their size.
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The activation time is strictly inside the stage horizon.
Every activation occurs before time one.