Intrinsic star operation on linear maps #
This file defines the star operation on linear maps: (star f) x = star (f (star x)).
This corresponds to a map being star-preserving, i.e., a map is self-adjoint iff it
is star-preserving.
Implementation notes #
Because there is a global star instance on H →ₗ[𝕜] H (defined as the linear map adjoint on
finite-dimensional Hilbert spaces), which is mathematically distinct from this star, we provide
this instance on WithConv (E →ₗ[R] F).
The reason we chose WithConv is because together with the convolution product from
Mathlib/RingTheory/Coalgebra/Convolution.lean, we get a ⋆-algebra when
star (WithConv.toConv comul) = WithConv.toConv (comm ∘ comul).
The intrinsic star operation on linear maps E →ₗ F defined by
(star f) x = star (f (star x)).
The involutive intrinsic star structure on linear maps.
Equations
- LinearMap.intrinsicInvolutiveStar = { toStar := LinearMap.intrinsicStar, star_involutive := ⋯ }
The intrinsic star additive monoid structure on linear maps.
Equations
- LinearMap.intrinsicStarAddMonoid = { toInvolutiveStar := LinearMap.intrinsicInvolutiveStar, star_add := ⋯ }
A linear map is self-adjoint (with respect to the intrinsic star) iff it is star-preserving.
Alias of LinearMap.IntrinsicStar.isSelfAdjoint_iff_map_star.
A linear map is self-adjoint (with respect to the intrinsic star) iff it is star-preserving.
A star-preserving linear map is self-adjoint (with respect to the intrinsic star).
Alias of IntrinsicStar.StarHomClass.isSelfAdjoint.
A star-preserving linear map is self-adjoint (with respect to the intrinsic star).
A linear map f : (m → R) →ₗ (n → R) is self-adjoint (with respect to the intrinsic star)
iff its corresponding matrix f.toMatrix' has all self-adjoint elements.
So star-preserving maps correspond to their matrices containing only self-adjoint elements.
Given a matrix A, A.toLin' is self-adjoint (with respect to the intrinsic star)
iff all its elements are self-adjoint.
Intrinsic star operation for (End R E)ˣ.
Equations
- One or more equations did not get rendered due to their size.