Equivalence of manifold differentiability with the basic definition for functions between #
vector spaces
The API in this file is mostly copied from Mathlib/Geometry/Manifold/ContMDiff/NormedSpace.lean,
providing the same statements for higher smoothness. In this file, we do the same for
differentiability.
Main definitions #
In addition to the above, this file provides two important definitions.
mvfderiv I f xis the manifold Fréchet derivative atx : Mof a vector-valued functionf : M → V, but taking values in the target normed spaceVinstead ofTangentSpace% (f x) V. Mathematically, this uses the global trivializationT V ≅ V × V, yielding an identificationT_v V ≅ Vfor eachv : V. In Lean, we post-compose the differentialmfderiv% f xwithNormedSpace.fromTangentSpace. IfVis a field, this coincides with the exterior derivative offas a section of the cotangent bundle. There is notationd% fformvfderiv I fvia a custom elaborator scoped to theManifoldnamespace, with a corresponding delaborator,mvfderivWithinwith notationd[s] fformvfderivWithin I f sin theManifoldnamespace: the analogous concept within a set, with analogous API lemmas
Main results #
This file contains
- results about the differentiability of scalar multiplication (
mfderiv_smuland friends), - basic lemmas about
mvfderiv(such as addition, subtraction, multiplication and constants), - analogous lemmas about
mvfderivWithin, - composition lemmas about
mvfderivWithinandmvfderiv.
Linear maps between normed spaces are differentiable #
Applying a linear map to a vector is differentiable within a set. Version in vector spaces. For
a version in nontrivial vector bundles, see MDifferentiableWithinAt.clm_apply_of_inCoordinates.
Applying a linear map to a vector is differentiable. Version in vector spaces. For a
version in nontrivial vector bundles, see MDifferentiableAt.clm_apply_of_inCoordinates.
Differentiability of scalar multiplication #
Eta-expanded form of MDifferentiableAt.smul
Eta-expanded form of MDifferentiableOn.smul
Eta-expanded form of MDifferentiable.smul
Exterior derivative of a vector-valued function #
mvfderivWithin I J f s x is the mfderiv of a vector-valued function f on M at x
within the set s, but taking values in the target normed space directly.
The difference to mfderivWithin is explained in the module-docstring for
Mathlib/Geometry/Manifold/MFDeriv/NormedSpace.lean.
Future: this could be generalised to functions into additive torsors over abelian Lie groups.
Equations
- d[s] g x = ↑(NormedSpace.fromTangentSpace (g x)) ∘SL mfderiv[s] g x
Instances For
mvfderiv I J f x is the mfderiv of a vector-valued function f on M at x,
but taking values in the target normed space directly.
The difference to mfderiv is explained in the module-docstring for
Mathlib/Geometry/Manifold/MFDeriv/NormedSpace.lean.
Future: this could be generalised to functions into additive torsors over abelian Lie groups.
Equations
- d% g x = ↑(NormedSpace.fromTangentSpace (g x)) ∘SL mfderiv% g x
Instances For
Alias of mvfderiv.
mvfderiv I J f x is the mfderiv of a vector-valued function f on M at x,
but taking values in the target normed space directly.
The difference to mfderiv is explained in the module-docstring for
Mathlib/Geometry/Manifold/MFDeriv/NormedSpace.lean.
Future: this could be generalised to functions into additive torsors over abelian Lie groups.
Equations
Instances For
d[s] f x (scoped to the Manifold namespace) elaborates to mvfderivWithin I f s x,
trying to determine I and J from the local context.
Equations
- One or more equations did not get rendered due to their size.
Instances For
d% f x (scoped to the Manifold namespace) elaborates to mvfderiv I f x,
trying to determine I and J from the local context.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Delaborator for mvfderivWithin.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Delaborator for mvfderiv.
Equations
- One or more equations did not get rendered due to their size.
Instances For
Eta-expanded form of mvfderivWithin_add
Eta-expanded form of mvfderivWithin_sub
Eta-expanded form of mvfderivWithin_neg
Eta-expanded form of mvfderivWithin_smul
Eta-expanded form of mvfderivWithin_mul
Eta-expanded form of mvfderiv_add
Alias of mvfderiv_add.
Eta-expanded form of mvfderiv_sub
Eta-expanded form of mvfderiv_neg
Eta-expanded form of mvfderiv_smul
Eta-expanded form of mvfderiv_mul
Alias of mvfderiv_zero.
For maps between vector spaces, mvfderivWithin and fderivWithin coincide.
For maps between vector spaces, mvfderiv and fderiv coincide.
For maps between vector spaces, mfderivWithin and fderivWithin coincide.
For maps between vector spaces, mfderiv and fderiv coincide.