OAI/Analysis/SphereIsometry/Alignment.lean

GitHub source file

2 declarations, 0 contain sorry, 0 declared as axioms

Alignment from an attained positive defect

The actual positive schedule supplies the invariant convex set; the actual return-map estimate and the proved fixed-point theorem supply its fixed point. The original center and scalar remain unchanged throughout the construction.

  1. def OAI.Tingley.aligned_of_return_fixed line 25

    Source documentation

    A fixed point of the genuine sphere return map gives the exact four chords.

    def aligned_of_return_fixed
        (f : UnitSphere X ≃ᵢ UnitSphere Y) (y : UnitSphere X)
        (t M : ℝ) (ht : 0 < t ∧ t < 1) (hb : HasDefectBound f M)
        (v : UnitSphere X) (hv : v ∈ extremalSphere f y t ht M)
        (hfixed : returnSphere f y t ht v = v) : AlignedConfiguration f y t M where
    …

    Mentions: OAI.Tingley.UnitSphere, OAI.Tingley.HasDefectBound, OAI.Tingley.extremalSphere, OAI.Tingley.returnSphere, OAI.Tingley.AlignedConfiguration

  2. theorem OAI.Tingley.exists_alignedConfiguration line 61

    Source documentation

    Alignment has no supplied invariant-set, contraction or fixed-point premise.

    theorem exists_alignedConfiguration [CompleteSpace X]
        (f : UnitSphere X ≃ᵢ UnitSphere Y) (y x₀ : UnitSphere X)
        (t M : ℝ) (ht : 0 < t ∧ t < 1) (hM : 0 < M)
        (hb : HasDefectBound f M) (hatt : signedDefect f t x₀ y = M) :
        Nonempty (AlignedConfiguration f y t M) := by
    …

    Mentions: OAI.Tingley.UnitSphere, OAI.Tingley.HasDefectBound, OAI.Tingley.signedDefect, OAI.Tingley.AlignedConfiguration