OAI/GroupTheory/PolycyclicRecognition/Algebra/RescaledBasisChange.lean

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2 declarations, 0 contain sorry, 0 declared as axioms

Exponential margins between two rescalings of the same basis

  1. theorem OAI.PolycyclicRecognition.repr_change_exponentialRescaleBasis line 14

    Source documentation

    Exact coordinate change between two exponential rescalings.

    theorem repr_change_exponentialRescaleBasis (b : Basis J ℝ L)
        (s t : J → ℝ) (r : ℝ) (x : L) (j : J) :
        (exponentialRescaleBasis b s r).repr x j =
          (exponentialRescaleBasis b t r).repr x j * Real.exp (r * (t j - s j)) := by
    …

    Mentions: OAI.PolycyclicRecognition.exponentialRescaleBasis

  2. theorem OAI.PolycyclicRecognition.norm_change_exponentialRescaleBasis_le line 29

    Source documentation

    A common difference between the exponents gives an exponential gain or loss in the whole coordinate maximum norm.

    theorem norm_change_exponentialRescaleBasis_le [Fintype J]
        (b : Basis J ℝ L) (s t : J → ℝ) {r α : ℝ} (hr : 0 ≤ r)
        (hgap : ∀ j, t j - s j ≤ α) (x : L) :
        ‖(exponentialRescaleBasis b s r).equivFun x‖ ≤
          Real.exp (r * α) * ‖(exponentialRescaleBasis b t r).equivFun x‖ := by
    …

    Mentions: OAI.PolycyclicRecognition.exponentialRescaleBasis