Continuous multilinear maps #
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We define continuous multilinear maps as maps from Π(i : ι), M₁ i
to M₂
which are multilinear
and continuous, by extending the space of multilinear maps with a continuity assumption.
Here, M₁ i
and M₂
are modules over a ring R
, and ι
is an arbitrary type, and all these
spaces are also topological spaces.
Main definitions #
continuous_multilinear_map R M₁ M₂
is the space of continuous multilinear maps fromΠ(i : ι), M₁ i
toM₂
. We show that it is anR
-module.
Implementation notes #
We mostly follow the API of multilinear maps.
Notation #
We introduce the notation M [×n]→L[R] M'
for the space of continuous n
-multilinear maps from
M^n
to M'
. This is a particular case of the general notion (where we allow varying dependent
types as the arguments of our continuous multilinear maps), but arguably the most important one,
especially when defining iterated derivatives.
- to_multilinear_map : multilinear_map R M₁ M₂
- cont : continuous self.to_multilinear_map.to_fun
Continuous multilinear maps over the ring R
, from Πi, M₁ i
to M₂
where M₁ i
and M₂
are modules over R
with a topological structure. In applications, there will be compatibility
conditions between the algebraic and the topological structures, but this is not needed for the
definition.
Instances for continuous_multilinear_map
- continuous_multilinear_map.has_sizeof_inst
- continuous_multilinear_map.continuous_map_class
- continuous_multilinear_map.has_coe_to_fun
- continuous_multilinear_map.has_zero
- continuous_multilinear_map.inhabited
- continuous_multilinear_map.has_smul
- continuous_multilinear_map.smul_comm_class
- continuous_multilinear_map.is_scalar_tower
- continuous_multilinear_map.is_central_scalar
- continuous_multilinear_map.mul_action
- continuous_multilinear_map.has_add
- continuous_multilinear_map.add_comm_monoid
- continuous_multilinear_map.has_neg
- continuous_multilinear_map.has_sub
- continuous_multilinear_map.add_comm_group
- continuous_multilinear_map.distrib_mul_action
- continuous_multilinear_map.module
- continuous_multilinear_map.has_op_norm
- continuous_multilinear_map.has_op_norm'
- continuous_multilinear_map.normed_add_comm_group
- continuous_multilinear_map.normed_add_comm_group'
- continuous_multilinear_map.normed_space
- continuous_multilinear_map.normed_space'
- continuous_multilinear_map.complete_space
- continuous_multilinear_map.has_continuous_const_smul
Equations
- continuous_multilinear_map.continuous_map_class = {coe := λ (f : continuous_multilinear_map R M₁ M₂), f.to_multilinear_map.to_fun, coe_injective' := _, map_continuous := _}
Equations
- continuous_multilinear_map.has_coe_to_fun = {coe := λ (f : continuous_multilinear_map R M₁ M₂), ⇑f}
See Note [custom simps projection]. We need to specify this projection explicitly in this case, because it is a composition of multiple projections.
Equations
- continuous_multilinear_map.simps.apply L₁ v = ⇑L₁ v
Equations
Equations
- continuous_multilinear_map.has_smul = {smul := λ (c : R') (f : continuous_multilinear_map A M₁ M₂), {to_multilinear_map := {to_fun := (c • f.to_multilinear_map).to_fun, map_add' := _, map_smul' := _}, cont := _}}
Equations
- continuous_multilinear_map.mul_action = function.injective.mul_action continuous_multilinear_map.to_multilinear_map continuous_multilinear_map.mul_action._proof_1 continuous_multilinear_map.mul_action._proof_2
Equations
- continuous_multilinear_map.has_add = {add := λ (f f' : continuous_multilinear_map R M₁ M₂), {to_multilinear_map := f.to_multilinear_map + f'.to_multilinear_map, cont := _}}
Equations
- continuous_multilinear_map.add_comm_monoid = function.injective.add_comm_monoid continuous_multilinear_map.to_multilinear_map continuous_multilinear_map.add_comm_monoid._proof_3 continuous_multilinear_map.add_comm_monoid._proof_4 continuous_multilinear_map.add_comm_monoid._proof_5 continuous_multilinear_map.add_comm_monoid._proof_6
Evaluation of a continuous_multilinear_map
at a vector as an add_monoid_hom
.
Equations
- continuous_multilinear_map.apply_add_hom m = {to_fun := λ (f : continuous_multilinear_map R M₁ M₂), ⇑f m, map_zero' := _, map_add' := _}
If f
is a continuous multilinear map, then f.to_continuous_linear_map m i
is the continuous
linear map obtained by fixing all coordinates but i
equal to those of m
, and varying the
i
-th coordinate.
Equations
- f.to_continuous_linear_map m i = {to_linear_map := {to_fun := (f.to_multilinear_map.to_linear_map m i).to_fun, map_add' := _, map_smul' := _}, cont := _}
The cartesian product of two continuous multilinear maps, as a continuous multilinear map.
Equations
- f.prod g = {to_multilinear_map := {to_fun := (f.to_multilinear_map.prod g.to_multilinear_map).to_fun, map_add' := _, map_smul' := _}, cont := _}
Combine a family of continuous multilinear maps with the same domain and codomains M' i
into a
continuous multilinear map taking values in the space of functions Π i, M' i
.
Equations
- continuous_multilinear_map.pi f = {to_multilinear_map := multilinear_map.pi (λ (i : ι'), (f i).to_multilinear_map), cont := _}
Restrict the codomain of a continuous multilinear map to a submodule.
Equations
- f.cod_restrict p h = {to_multilinear_map := f.to_multilinear_map.cod_restrict p h, cont := _}
The evaluation map from ι → M₂
to M₂
is multilinear at a given i
when ι
is subsingleton.
Equations
- continuous_multilinear_map.of_subsingleton R M₂ i' = {to_multilinear_map := multilinear_map.of_subsingleton R M₂ i', cont := _}
The constant map is multilinear when ι
is empty.
Equations
- continuous_multilinear_map.const_of_is_empty R M₁ m = {to_multilinear_map := multilinear_map.const_of_is_empty R M₁ m, cont := _}
If g
is continuous multilinear and f
is a collection of continuous linear maps,
then g (f₁ m₁, ..., fₙ mₙ)
is again a continuous multilinear map, that we call
g.comp_continuous_linear_map f
.
Equations
- g.comp_continuous_linear_map f = {to_multilinear_map := {to_fun := (g.to_multilinear_map.comp_linear_map (λ (i : ι), (f i).to_linear_map)).to_fun, map_add' := _, map_smul' := _}, cont := _}
Composing a continuous multilinear map with a continuous linear map gives again a continuous multilinear map.
Equations
- g.comp_continuous_multilinear_map f = {to_multilinear_map := {to_fun := (g.to_linear_map.comp_multilinear_map f.to_multilinear_map).to_fun, map_add' := _, map_smul' := _}, cont := _}
continuous_multilinear_map.pi
as an equiv
.
Equations
- continuous_multilinear_map.pi_equiv = {to_fun := continuous_multilinear_map.pi (λ (i : ι'), _inst_22 i), inv_fun := λ (f : continuous_multilinear_map R M₁ (Π (i : ι'), M' i)) (i : ι'), (continuous_linear_map.proj i).comp_continuous_multilinear_map f, left_inv := _, right_inv := _}
An equivalence of the index set defines an equivalence between the spaces of continuous multilinear maps. This is the forward map of this equivalence.
Equations
An equivalence of the index set defines an equivalence between the spaces of continuous
multilinear maps. In case of normed spaces, this is a linear isometric equivalence, see
continuous.multilinear_map.dom_dom_congrₗᵢ
.
Equations
In the specific case of continuous multilinear maps on spaces indexed by fin (n+1)
, where one
can build an element of Π(i : fin (n+1)), M i
using cons
, one can express directly the
additivity of a multilinear map along the first variable.
In the specific case of continuous multilinear maps on spaces indexed by fin (n+1)
, where one
can build an element of Π(i : fin (n+1)), M i
using cons
, one can express directly the
multiplicativity of a multilinear map along the first variable.
Additivity of a continuous multilinear map along all coordinates at the same time,
writing f (m + m')
as the sum of f (s.piecewise m m')
over all sets s
.
If f
is continuous multilinear, then f (Σ_{j₁ ∈ A₁} g₁ j₁, ..., Σ_{jₙ ∈ Aₙ} gₙ jₙ)
is the
sum of f (g₁ (r 1), ..., gₙ (r n))
where r
ranges over all functions with r 1 ∈ A₁
, ...,
r n ∈ Aₙ
. This follows from multilinearity by expanding successively with respect to each
coordinate.
If f
is continuous multilinear, then f (Σ_{j₁} g₁ j₁, ..., Σ_{jₙ} gₙ jₙ)
is the sum of
f (g₁ (r 1), ..., gₙ (r n))
where r
ranges over all functions r
. This follows from
multilinearity by expanding successively with respect to each coordinate.
Reinterpret an A
-multilinear map as an R
-multilinear map, if A
is an algebra over R
and their actions on all involved modules agree with the action of R
on A
.
Equations
Equations
- continuous_multilinear_map.has_neg = {neg := λ (f : continuous_multilinear_map R M₁ M₂), {to_multilinear_map := {to_fun := (-f.to_multilinear_map).to_fun, map_add' := _, map_smul' := _}, cont := _}}
Equations
- continuous_multilinear_map.has_sub = {sub := λ (f g : continuous_multilinear_map R M₁ M₂), {to_multilinear_map := {to_fun := (f.to_multilinear_map - g.to_multilinear_map).to_fun, map_add' := _, map_smul' := _}, cont := _}}
Equations
- continuous_multilinear_map.add_comm_group = function.injective.add_comm_group continuous_multilinear_map.to_multilinear_map continuous_multilinear_map.add_comm_group._proof_6 continuous_multilinear_map.add_comm_group._proof_7 continuous_multilinear_map.add_comm_group._proof_8 continuous_multilinear_map.add_comm_group._proof_9 continuous_multilinear_map.add_comm_group._proof_10 continuous_multilinear_map.add_comm_group._proof_11 continuous_multilinear_map.add_comm_group._proof_12
Multiplicativity of a continuous multilinear map along all coordinates at the same time,
writing f (λ i, c i • m i)
as (∏ i, c i) • f m
.
Equations
- continuous_multilinear_map.distrib_mul_action = function.injective.distrib_mul_action {to_fun := continuous_multilinear_map.to_multilinear_map _inst_7, map_zero' := _, map_add' := _} continuous_multilinear_map.distrib_mul_action._proof_3 continuous_multilinear_map.distrib_mul_action._proof_4
The space of continuous multilinear maps over an algebra over R
is a module over R
, for the
pointwise addition and scalar multiplication.
Equations
- continuous_multilinear_map.module = function.injective.module R' {to_fun := continuous_multilinear_map.to_multilinear_map _inst_6, map_zero' := _, map_add' := _} continuous_multilinear_map.module._proof_3 continuous_multilinear_map.module._proof_4
Linear map version of the map to_multilinear_map
associating to a continuous multilinear map
the corresponding multilinear map.
Equations
continuous_multilinear_map.pi
as a linear_equiv
.
Equations
The continuous multilinear map on A^ι
, where A
is a normed commutative algebra
over 𝕜
, associating to m
the product of all the m i
.
See also continuous_multilinear_map.mk_pi_algebra_fin
.
Equations
- continuous_multilinear_map.mk_pi_algebra R ι A = {to_multilinear_map := multilinear_map.mk_pi_algebra R ι A _inst_1, cont := _}
The continuous multilinear map on A^n
, where A
is a normed algebra over 𝕜
, associating to
m
the product of all the m i
.
See also: continuous_multilinear_map.mk_pi_algebra
.
Equations
- continuous_multilinear_map.mk_pi_algebra_fin R n A = {to_multilinear_map := multilinear_map.mk_pi_algebra_fin R n A _inst_3, cont := _}
Given a continuous R
-multilinear map f
taking values in R
, f.smul_right z
is the
continuous multilinear map sending m
to f m • z
.
Equations
- f.smul_right z = {to_multilinear_map := f.to_multilinear_map.smul_right z, cont := _}