Reversal Wave Synthesis
Abstract
The reversal witness coefficients synthesize the stated smooth divergence-free real cosine fields.
Definition 1.1 (character).
Lean statement: D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.character
Formalization. D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.character (✓ std3).
Source. Repository-derived.
Commentary.
The character exp(i*k.x), written in real sine/cosine coordinates.
Definition 1.2 (synthesis).
Lean statement: D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.synthesis
Formalization. D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.synthesis (✓ std3).
Source. Repository-derived.
Commentary.
Literal finite synthesis using the same four frequencies and coefficients.
Definition 1.3 (realVelocity).
Lean statement: D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.realVelocity
Formalization. D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.realVelocity (✓ std3).
Source. Repository-derived.
Commentary.
The actual smooth velocity field, independent of the third coordinate.
Theorem 1.4 (synthesis eq realVelocity).
Lean statement: D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.synthesis_eq_realVelocity
Proof. Machine-checked in Lean as D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.synthesis_eq_realVelocity (✓ std3). ∎
Source. Repository-derived.
Commentary.
The finite Fourier data is exactly the advertised real cosine field.
Theorem 1.5 (realVelocity contDiff).
Lean statement: D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.realVelocity_contDiff
Proof. Machine-checked in Lean as D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.realVelocity_contDiff (✓ std3). ∎
Source. Repository-derived.
Commentary.
Both active spatial coordinates are jointly smooth to every finite order.
Theorem 1.6 (realVelocity periodic).
Lean statement: D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.realVelocity_periodic
Proof. Machine-checked in Lean as D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.realVelocity_periodic (✓ std3). ∎
Source. Repository-derived.
Commentary.
The literal field has the correct 2*pi period in each active coordinate.
Theorem 1.7 (realVelocity divergence).
Lean statement: D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.realVelocity_divergence
Proof. Machine-checked in Lean as D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.realVelocity_divergence (✓ std3). ∎
Source. Repository-derived.
Commentary.
Ordinary coordinate derivatives give zero divergence; no symbolic ‘divergence-free’ label is used as a premise.
References
- Truth anchor:
D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.character - Truth anchor:
D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.realVelocity - Truth anchor:
D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.realVelocity_contDiff - Truth anchor:
D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.realVelocity_divergence - Truth anchor:
D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.realVelocity_periodic - Truth anchor:
D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.synthesis - Truth anchor:
D5/S3/FluidDynamics/Fourier/ReversalWaveSynthesis.synthesis_eq_realVelocity - Dependency: D5/S3/FluidDynamics/Fourier/LowModeReversalWitness