OAI/Analysis/Nonexpansive/ScalarNormalization.lean
10 declarations, 0 contain sorry, 0 declared as axioms
Scalar normalization in the original norm
We move the actual invariant set by a positive scalar and conjugate its map. No norm instance is replaced. Minimality and absence of fixed points are transported by the explicit inverse scalar multiplication.
- def
OAI.ReflexiveFixedPoints.scaledSubtypeEquivline 26Source documentation
The actual homothety between a set and its nonzero scalar image.
def scaledSubtypeEquiv (K : Set X) (c : ℝ) (hc : c ≠ 0) : K ≃ (c • K : Set X) where …
- theorem
OAI.ReflexiveFixedPoints.scaledSubtypeEquiv_applyline 35 - theorem
OAI.ReflexiveFixedPoints.scaledSubtypeEquiv_symm_applyline 38 - def
OAI.ReflexiveFixedPoints.scaledMapline 43Source documentation
Conjugate an actual selfmap by the scalar bijection.
def scaledMap (K : Set X) (T : K → K) (c : ℝ) (hc : c ≠ 0) : (c • K : Set X) → (c • K : Set X) := … - theorem
OAI.ReflexiveFixedPoints.scaledMap_fixed_iffline 48Source documentation
Fixed points pull back through the actual scalar change of variables.
theorem scaledMap_fixed_iff (K : Set X) (T : K → K) (c : ℝ) (hc : c ≠ 0) (y : (c • K : Set X)) : scaledMap K T c hc y = y ↔ T ((scaledSubtypeEquiv K c hc).symm y) = (scaledSubtypeEquiv K c hc).symm y := by …Mentions: OAI.ReflexiveFixedPoints.scaledMap, OAI.ReflexiveFixedPoints.scaledSubtypeEquiv
- theorem
OAI.ReflexiveFixedPoints.scaledMap_nonexpansiveline 61Source documentation
Conjugation by a positive homothety preserves nonexpansiveness.
theorem scaledMap_nonexpansive (K : Set X) (T : K → K) (hT : LipschitzWith 1 T) (c : ℝ) (hc : 0 < c) : LipschitzWith 1 (scaledMap K T c hc.ne') := by …Mentions: OAI.ReflexiveFixedPoints.scaledMap
- theorem
OAI.ReflexiveFixedPoints.scaledMap_minimalline 85Source documentation
The image under a positive homothety retains minimality.
theorem scaledMap_minimal (K : Set X) (T : K → K) (hT : MinimalInvariant K T) (c : ℝ) (hc : 0 < c) : MinimalInvariant (c • K) (scaledMap K T c hc.ne') := by …Mentions: OAI.ReflexiveFixedPoints.MinimalInvariant, OAI.ReflexiveFixedPoints.scaledMap
- theorem
OAI.ReflexiveFixedPoints.MinimalInvariantData.diam_posline 117Source documentation
A fixed-point-free invariant set cannot have zero diameter.
theorem diam_pos (D : MinimalInvariantData (X := X)) : 0 < Metric.diam D.K := by …
- def
OAI.ReflexiveFixedPoints.MinimalInvariantData.scaledline 124Source documentation
All structural properties survive the actual scalar homothety.
def scaled (D : MinimalInvariantData (X := X)) (hX : CanonicallyReflexive X) …
Mentions: OAI.ReflexiveFixedPoints.MinimalInvariantData, OAI.ReflexiveFixedPoints.CanonicallyReflexive
- theorem
OAI.ReflexiveFixedPoints.MinimalInvariantData.scaled_inv_diamline 140Source documentation
Diameter is exactly one after inverse-diameter scaling.
theorem scaled_inv_diam (D : MinimalInvariantData (X := X)) …