LeanAide GPT-4 documentation

Module: Mathlib.Analysis.NormedSpace.OperatorNorm.Mul


ContinuousLinearMap.op_norm_lsmul

theorem ContinuousLinearMap.op_norm_lsmul : βˆ€ (π•œ : Type u_1) {E : Type u_2} [inst : NontriviallyNormedField π•œ] [inst_1 : NormedAddCommGroup E] [inst_2 : NormedSpace π•œ E] (π•œ' : Type u_3) [inst_3 : NormedField π•œ'] [inst_4 : NormedAlgebra π•œ π•œ'] [inst_5 : NormedSpace π•œ' E] [inst_6 : IsScalarTower π•œ π•œ' E] [inst_7 : Nontrivial E], β€–ContinuousLinearMap.lsmul π•œ π•œ'β€– = 1

This theorem states that for any given type π•œ and type E (under the conditions that π•œ is a non-trivially normed field, E is a normed additive commutative group, E is a normed space over π•œ, and E is non-trivial), and for any additional type π•œ' (under the conditions that π•œ' is a normed field, E is a normed space over π•œ', and π•œ', π•œ and E form a scalar tower), the operator norm of the left scalar multiplication continuous linear map from π•œ to π•œ' is equal to 1. In simpler terms, this theorem describes a property of scalar multiplication in certain mathematical structures, stating that when these conditions are met, the "size" (or norm) of the multiplication operation stays constant at 1.

More concisely: Given non-trivially normed fields π•œ and π•œ', a normed additive commutative group E that is a normed space over both π•œ and π•œ', and forms a scalar tower, the operator norm of the scalar multiplication map from π•œ to π•œ' is equal to 1.

ContinuousLinearMap.op_norm_lsmul_le

theorem ContinuousLinearMap.op_norm_lsmul_le : βˆ€ {π•œ : Type u_1} {E : Type u_2} [inst : NontriviallyNormedField π•œ] [inst_1 : SeminormedAddCommGroup E] [inst_2 : NormedSpace π•œ E] {π•œ' : Type u_3} [inst_3 : NormedField π•œ'] [inst_4 : NormedAlgebra π•œ π•œ'] [inst_5 : NormedSpace π•œ' E] [inst_6 : IsScalarTower π•œ π•œ' E], β€–ContinuousLinearMap.lsmul π•œ π•œ'β€– ≀ 1

This theorem states that in any semi-normed group, the operator norm of the left scalar multiplication operator (`lsmul`) is at most 1. This is applicable for any non-trivially normed field `π•œ`, any semi-normed add-commutative group `E` that is also a normed space over `π•œ`, any normed field `π•œ'` that is a normed algebra over `π•œ` and a normed space over `π•œ'`, and any scalar tower structure on `E` over `π•œ` and `π•œ'`.

More concisely: In any semi-normed group that is a normed space over a non-trivially normed field, the operator norm of the left scalar multiplication is bounded by 1.

RegularNormedAlgebra.isometry_mul'

theorem RegularNormedAlgebra.isometry_mul' : βˆ€ {π•œ : Type u_1} [inst : NontriviallyNormedField π•œ] {π•œ' : Type u_3} [inst_1 : NonUnitalSeminormedRing π•œ'] [inst_2 : NormedSpace π•œ π•œ'] [inst_3 : IsScalarTower π•œ π•œ' π•œ'] [inst_4 : SMulCommClass π•œ π•œ' π•œ'] [self : RegularNormedAlgebra π•œ π•œ'], Isometry ⇑(ContinuousLinearMap.mul π•œ π•œ')

This theorem states that the left regular representation of an algebra on itself is an isometry. In other words, for any nontrivially normed field π•œ and any non-unital seminormed ring π•œ', given the circumstances where π•œ' is a normed space over π•œ, π•œ is a scalar tower over π•œ', and π•œ and π•œ' form a commutative multiplication class, and π•œ' is a regular normed algebra over π•œ, the continuous bilinear map representing multiplication in π•œ' preserves the distance between elements when viewed as a function from π•œ' to π•œ'.

More concisely: The left regular representation of a regular normed algebra over a scalar tower preserves the distance between elements when viewed as a bilinear map from the algebra to the scalar field.