OAI/Probability/InvariantIsing/Magnetic/MagneticFieldMinimum.lean

GitHub source file

12 declarations, 0 contain sorry, 0 declared as axioms

The finite prescribed-magnetization functional has an attained bias minimum at every interior magnetization. No optimizer or concavity premise is used.

  1. def OAI.InvariantIsing.magneticBiasObjective line 16

    Source documentation

    The finite canonical field value with the magnetization constraint.

    Also declared: ComparatorChallenges/InvariantIsing.lean:149 (same declaration text).

    def magneticBiasObjective (h : FieldStep) (s b : ℝ) : ℝ :=
    …

    Mentions: OAI.InvariantIsing.FieldStep

  2. def OAI.InvariantIsing.constrainedFieldValue line 20

    Source documentation

    The prescribed-magnetization field functional from (mag:constrained-functional).

    Distinct definitions of this name: ComparatorChallenges/InvariantIsing.lean:151 (same statement text; different proof or body). Qualify references as OAI.InvariantIsing.constrainedFieldValue@path.

    def constrainedFieldValue (h : FieldStep) (s : ℝ) : ℝ :=
    …

    Mentions: OAI.InvariantIsing.FieldStep

  3. lemma OAI.InvariantIsing.magneticBiasObjective_lower line 23
  4. lemma OAI.InvariantIsing.magneticBiasObjective_bddBelow line 32
  5. lemma OAI.InvariantIsing.continuous_magneticBiasObjective line 39
  6. lemma OAI.InvariantIsing.hasDerivAt_magneticBiasObjective line 43
  7. lemma OAI.InvariantIsing.exists_magneticBias_minimum line 51

    Source documentation

    Linear coercivity gives a genuine global optimizer, including field profiles with tied heights or zero increments.

    lemma exists_magneticBias_minimum (h : FieldStep) {s : ℝ} (hs : |s| < 1) :
        ∃ b : ℝ, ∀ c : ℝ, magneticBiasObjective h s b ≤ magneticBiasObjective h s c := by
    …

    Mentions: OAI.InvariantIsing.FieldStep, OAI.InvariantIsing.magneticBiasObjective

  8. lemma OAI.InvariantIsing.constrainedFieldValue_eq_at_minimum line 85
  9. lemma OAI.InvariantIsing.constrainedFieldValue_attained line 93
  10. lemma OAI.InvariantIsing.magneticBiasMean_eq_of_minimum line 101

    Source documentation

    At any minimizing bias the actual physical mean spin equals the prescribed magnetization.

    lemma magneticBiasMean_eq_of_minimum (h : FieldStep) {s b : ℝ}
        (hmin : ∀ c : ℝ, magneticBiasObjective h s b ≤ magneticBiasObjective h s c) :
        fieldBiasMean h b = s := by
    …

    Mentions: OAI.InvariantIsing.FieldStep, OAI.InvariantIsing.magneticBiasObjective, OAI.InvariantIsing.fieldBiasMean

  11. lemma OAI.InvariantIsing.constrainedFieldValue_coe_iInf line 109

    Source documentation

    The real minimum agrees exactly with the extended-real infimum.

    lemma constrainedFieldValue_coe_iInf (h : FieldStep) {s : ℝ} (hs : |s| < 1) :
        (constrainedFieldValue h s : EReal) =
          ⨅ b : ℝ, ((fieldValue h b - b * s : ℝ) : EReal) := by
    …

    Mentions: OAI.InvariantIsing.FieldStep, OAI.InvariantIsing.fieldValue

  12. lemma OAI.InvariantIsing.magneticBias_minimum_bound line 122

    Source documentation

    Interior minimizing biases are bounded uniformly on bounded-height families of fields.

    lemma magneticBias_minimum_bound (h : FieldStep) {s b C : ℝ} (hs : |s| < 1)
        (hC : h.height (Fin.last h.depth) ≤ C)
        (hmin : ∀ c : ℝ, magneticBiasObjective h s b ≤ magneticBiasObjective h s c) :
        |b| ≤ (Real.log 2 + C / 2) / (1 - |s|) := by
    …

    Mentions: OAI.InvariantIsing.FieldStep, OAI.InvariantIsing.magneticBiasObjective