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.
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 #
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 J 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 J 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.