IndisputableMonolith.ClassicalBridge.Fluids.Galerkin2D
The module defines the 2D Fourier mode truncation and associated operators for a finite-dimensional Galerkin model of the Navier-Stokes equations. Researchers building the Recognition Science fluids pipeline cite it as the discrete base layer (M1). It consists entirely of type and operator definitions with no theorems or proofs.
claimThe 2D Galerkin model is constructed from modes $m=(k_1,k_2)∈ℤ²$, finite truncations, velocity coefficients $u_m$, the state space, wavenumber-squared terms $k²$, Laplacian coefficients, the convection operator, the projected right-hand side, and the discrete energy functional.
background
This module introduces the finite-dimensional 2D Galerkin discretization in the ClassicalBridge.Fluids domain. Core definitions include Mode2 as a pair of integers representing a 2D Fourier mode, modeTrunc for selecting finite subsets, the set of active modes, VelCoeff for velocity coefficients on those modes, GalerkinState as the full coefficient vector, kSq for the squared wavenumber, laplacianCoeff, ConvectionOp for the projected nonlinear term, galerkinNSRHS for the right-hand side of the truncated equations, discreteEnergy, and EnergySkewHypothesis. The module imports Mathlib components for inner-product spaces, calculus, integers, finsets, and tactics to support these constructions.
proof idea
This is a definition module, no proofs.
why it matters in Recognition Science
The module supplies the base discrete 2D Galerkin model (Milestone M1) that is imported by LNALSemantics for spatial encoding, by Simulation2D for the one-step bridge, by CPM2D for the CPM core instantiation with explicit hypotheses, by ContinuumLimit2D for the embedding of truncated coefficients into the infinite Fourier state, and by Regularity2D for the top-level composition theorem that concludes an abstract continuum solution exists.
scope and limits
- Does not prove any analytic inequalities or estimates for the fluid equations.
- Does not treat the 3D case or other spatial dimensions.
- Does not implement time-stepping or numerical simulation.
- Does not address boundary conditions or external forcing beyond the basic projected system.
- Does not discharge the EnergySkewHypothesis; it only declares the structure.
used by (5)
declarations in this module (19)
-
abbrev
Mode2 -
def
modeTrunc -
def
modes -
lemma
mem_modes_iff -
abbrev
VelCoeff -
abbrev
GalerkinState -
def
kSq -
def
laplacianCoeff -
def
ConvectionOp -
def
galerkinNSRHS -
def
discreteEnergy -
structure
EnergySkewHypothesis -
theorem
inviscid_energy_deriv_zero -
lemma
laplacianCoeff_inner_self_nonpos -
theorem
viscous_energy_deriv_le_zero -
theorem
viscous_energy_deriv_nonpos -
theorem
viscous_energy_antitone -
theorem
viscous_energy_bound_from_initial -
theorem
viscous_norm_bound_from_initial