OAI/MathematicalPhysics/DefocusingNLS/Nonlinear/ParameterOpenness.lean

GitHub source file

6 declarations, 0 contain sorry, 0 declared as axioms

Filling an open neighborhood with physical parameters

The finite-dimensional step used in the proof of Theorem thm:blowup. Brouwer's theorem gives a zero for a continuous perturbation of an invertible linear parameter map when the boundary error is sufficiently small.

  1. theorem OAI.DefocusingNLS.continuous_perturbation_covers_ball line 18

    Source documentation

    A continuous perturbation of the identity on a ball covers the smaller ball.

    theorem continuous_perturbation_covers_ball {E : Type*}
        [NormedAddCommGroup E] [NormedSpace ℝ E] [FiniteDimensional ℝ E]
        (r δ : ℝ) (hr : 0 ≤ r)
        (f : closedBall (0 : E) r → E) (hf : Continuous f)
        (herror : ∀ x, ‖f x - x.val‖ ≤ δ) :
        closedBall (0 : E) (r - δ) ⊆ Set.range f := by
    …
  2. theorem OAI.DefocusingNLS.zero_of_small_continuous_error line 46

    Source documentation

    The zero-existence specialization used after preconditioning by the invertible physical-parameter matrix.

    theorem zero_of_small_continuous_error {E : Type*}
        [NormedAddCommGroup E] [NormedSpace ℝ E] [FiniteDimensional ℝ E]
        (r δ : ℝ) (hr : 0 ≤ r) (hδ : δ ≤ r)
        (f : closedBall (0 : E) r → E) (hf : Continuous f)
        (herror : ∀ x, ‖f x - x.val‖ ≤ δ) :
        ∃ x, f x = 0 := by
    …
  3. theorem OAI.DefocusingNLS.zero_of_near_invertible_linear_map line 57

    Source documentation

    The version applied to a map close to an invertible physical-parameter matrix, after multiplication by its inverse.

    theorem zero_of_near_invertible_linear_map {E : Type*}
        [NormedAddCommGroup E] [NormedSpace ℝ E] [FiniteDimensional ℝ E]
        (C : E ≃L[ℝ] E) (r δ : ℝ) (hr : 0 ≤ r) (hδ : δ ≤ r)
        (f : closedBall (0 : E) r → E) (hf : Continuous f)
        (herror : ∀ x, ‖C.symm (f x) - x.val‖ ≤ δ) :
        ∃ x, f x = 0 := by
    …
  4. abbrev OAI.DefocusingNLS.PhysicalParameters line 69

    Source documentation

    Phase, twelve translations, and logarithmic blowup time.

    abbrev PhysicalParameters := ℝ × (Fin 12 → ℝ) × ℝ
  5. def OAI.DefocusingNLS.leadingParameterMap line 72

    Source documentation

    The leading parameter map in equation nl:leading-expansion.

    def leadingParameterMap (b : ℝ) (d : PhysicalParameters) : PhysicalParameters :=
    …

    Mentions: OAI.DefocusingNLS.PhysicalParameters

  6. theorem OAI.DefocusingNLS.leadingParameterMap_involutive line 76

    Source documentation

    The leading matrix is its own inverse, for every phase frequency.

    theorem leadingParameterMap_involutive (b : ℝ) :
        Function.Involutive (leadingParameterMap b) := by
    …

    Mentions: OAI.DefocusingNLS.leadingParameterMap