Normed space structure on ℂ
. #
This file gathers basic facts of analytic nature on the complex numbers.
Main results #
This file registers ℂ
as a normed field, expresses basic properties of the norm, and gives tools
on the real vector space structure of ℂ
. Notably, it defines the following functions in the
namespace Complex
.
Name | Type | Description |
---|---|---|
equivRealProdCLM |
ℂ ≃L[ℝ] ℝ × ℝ | The natural ContinuousLinearEquiv from ℂ to ℝ × ℝ |
reCLM |
ℂ →L[ℝ] ℝ | Real part function as a ContinuousLinearMap |
imCLM |
ℂ →L[ℝ] ℝ | Imaginary part function as a ContinuousLinearMap |
ofRealCLM |
ℝ →L[ℝ] ℂ | Embedding of the reals as a ContinuousLinearMap |
ofRealLI |
ℝ →ₗᵢ[ℝ] ℂ | Embedding of the reals as a LinearIsometry |
conjCLE |
ℂ ≃L[ℝ] ℂ | Complex conjugation as a ContinuousLinearEquiv |
conjLIE |
ℂ ≃ₗᵢ[ℝ] ℂ | Complex conjugation as a LinearIsometryEquiv |
We also register the fact that ℂ
is an RCLike
field.
Equations
- One or more equations did not get rendered due to their size.
Equations
- Complex.instNormedAlgebraOfReal = NormedAlgebra.mk ⋯
The module structure from Module.complexToReal
is a normed space.
Equations
- NormedSpace.complexToReal = NormedSpace.restrictScalars ℝ ℂ E
The algebra structure from Algebra.complexToReal
is a normed algebra.
Equations
- NormedAlgebra.complexToReal = NormedAlgebra.restrictScalars ℝ ℂ A
Alias of Complex.norm_natCast
.
Alias of Complex.norm_intCast
.
Alias of Complex.norm_ratCast
.
Alias of Complex.nnnorm_natCast
.
Alias of Complex.nnnorm_intCast
.
Alias of Complex.isUniformEmbedding_equivRealProd
.
The natural ContinuousLinearEquiv
from ℂ
to ℝ × ℝ
.
Equations
- Complex.equivRealProdCLM = Complex.equivRealProdLm.toContinuousLinearEquivOfBounds 1 (√2) Complex.equivRealProd_apply_le' Complex.equivRealProdCLM.proof_2
Instances For
The abs
function on ℂ
is proper.
The normSq
function on ℂ
is proper.
Continuous linear map version of the real part function, from ℂ
to ℝ
.
Equations
- Complex.reCLM = Complex.reLm.mkContinuous 1 Complex.reCLM.proof_1
Instances For
Alias of Complex.uniformlyContinuous_re
.
Continuous linear map version of the imaginary part function, from ℂ
to ℝ
.
Equations
- Complex.imCLM = Complex.imLm.mkContinuous 1 Complex.imCLM.proof_1
Instances For
Alias of Complex.uniformlyContinuous_im
.
The complex-conjugation function from ℂ
to itself is an isometric linear equivalence.
Equations
- Complex.conjLIE = { toLinearEquiv := Complex.conjAe.toLinearEquiv, norm_map' := Complex.abs_conj }
Instances For
The only continuous ring homomorphisms from ℂ
to ℂ
are the identity and the complex
conjugation.
Continuous linear equiv version of the conj function, from ℂ
to ℂ
.
Equations
- Complex.conjCLE = { toLinearEquiv := Complex.conjLIE.toLinearEquiv, continuous_toFun := Complex.conjCLE.proof_1, continuous_invFun := Complex.conjCLE.proof_2 }
Instances For
Linear isometry version of the canonical embedding of ℝ
in ℂ
.
Equations
- Complex.ofRealLI = { toLinearMap := Complex.ofRealAm.toLinearMap, norm_map' := Complex.norm_real }
Instances For
The only continuous ring homomorphism from ℝ
to ℂ
is the identity.
Continuous linear map version of the canonical embedding of ℝ
in ℂ
.
Equations
- Complex.ofRealCLM = Complex.ofRealLI.toContinuousLinearMap
Instances For
Equations
- One or more equations did not get rendered due to their size.
We show that the partial order and the topology on ℂ
are compatible.
We turn this into an instance scoped to ComplexOrder
.
We have to repeat the lemmas about RCLike.re
and RCLike.im
as they are not syntactic
matches for Complex.re
and Complex.im
.
We do not have this problem with ofReal
and conj
, although we repeat them anyway for
discoverability and to avoid the need to unify 𝕜
.
Define the "slit plane" ℂ ∖ ℝ≤0
and provide some API #
The slit plane is the complex plane with the closed negative real axis removed.
Instances For
Alias of Complex.natCast_mem_slitPlane
.
The slit plane includes the open unit ball of radius 1
around 1
.
The slit plane includes the open unit ball of radius 1
around 1
.