OAI/Probability/InvariantIsing/Magnetic/MagneticImplicitBias.lean

GitHub source file

3 declarations, 0 contain sorry, 0 declared as axioms

Parametric inversion of a strictly increasing physical mean spin. This supplies the finite-dimensional inverse-coordinate and envelope steps without assuming differentiability of the minimizing bias.

  1. lemma OAI.InvariantIsing.parametric_bias_continuousAt line 16
  2. lemma OAI.InvariantIsing.parametric_bias_hasDerivAt line 41

    Source documentation

    The implicit bias derivative follows from the derivative of the actual mean-spin map and the local root equation.

    lemma parametric_bias_hasDerivAt {A : ℝ × ℝ → ℝ} {b : ℝ → ℝ} {t s a c : ℝ}
        (hb : ContinuousAt b t) (hc : c ≠ 0)
        (hA : HasFDerivAt A (pairLinear a c) (t, b t))
        (he : ∀ᶠ q in 𝓝 t, A (q, b q) = s) :
        HasDerivAt b (-a / c) t := by
    …
  3. lemma OAI.InvariantIsing.parametric_bias_envelope line 74

    Source documentation

    Envelope differentiation with the bias response derived, rather than postulated, from the physical mean-spin equation.

    lemma parametric_bias_envelope {U A : ℝ × ℝ → ℝ} {b : ℝ → ℝ}
        {t s a c v : ℝ} (hb : ContinuousAt b t) (hc : c ≠ 0)
        (hA : HasFDerivAt A (pairLinear a c) (t, b t))
        (he : ∀ᶠ q in 𝓝 t, A (q, b q) = s)
        (hU : HasFDerivAt U (pairLinear v s) (t, b t)) :
        HasDerivAt (fun q => U (q, b q) - b q * s) v t := by
    …