A function f
satisfies is_bounded_linear_map 𝕜 f
if it is linear and satisfies the
inequality ∥ f x ∥ ≤ M * ∥ x ∥
for some positive constant M
.
A continuous linear map satisfies is_bounded_linear_map
Construct a linear map from a function f
satisfying is_bounded_linear_map 𝕜 f
.
Equations
Construct a continuous linear map from is_bounded_linear_map
Equations
- hf.to_continuous_linear_map = {to_linear_map := {to_fun := (is_bounded_linear_map.to_linear_map f hf).to_fun, map_add' := _, map_smul' := _}, cont := _}
Taking the cartesian product of two continuous linear maps is a bounded linear operation.
Taking the cartesian product of two continuous multilinear maps is a bounded linear operation.
Given a fixed continuous linear map g
, associating to a continuous multilinear map f
the
continuous multilinear map f (g m₁, ..., g mₙ)
is a bounded linear operation.
- add_left : ∀ (x₁ x₂ : E) (y : F), f (x₁ + x₂, y) = f (x₁, y) + f (x₂, y)
- smul_left : ∀ (c : 𝕜) (x : E) (y : F), f (c • x, y) = c • f (x, y)
- add_right : ∀ (x : E) (y₁ y₂ : F), f (x, y₁ + y₂) = f (x, y₁) + f (x, y₂)
- smul_right : ∀ (c : 𝕜) (x : E) (y : F), f (x, c • y) = c • f (x, y)
- bound : ∃ (C : ℝ) (H : C > 0), ∀ (x : E) (y : F), ∥f (x, y)∥ ≤ C * ∥x∥ * ∥y∥
A map f : E × F → G
satisfies is_bounded_bilinear_map 𝕜 f
if it is bilinear and
continuous.
The function continuous_linear_map.smul_right
, associating to a continuous linear map
f : E → 𝕜
and a scalar c : F
the tensor product f ⊗ c
as a continuous linear map from E
to
F
, is a bounded bilinear map.
The composition of a continuous linear map with a continuous multilinear map is a bounded bilinear operation.
Definition of the derivative of a bilinear map f
, given at a point p
by
q ↦ f(p.1, q.2) + f(q.1, p.2)
as in the standard formula for the derivative of a product.
We define this function here a bounded linear map from E × F
to G
. The fact that this
is indeed the derivative of f
is proved in is_bounded_bilinear_map.has_fderiv_at
in
fderiv.lean
The derivative of a bounded bilinear map at a point p : E × F
, as a continuous linear map
from E × F
to G
.
Equations
- h.deriv p = (h.linear_deriv p).mk_continuous_of_exists_bound _
The function lmul_left_right : 𝕜' × 𝕜' → (𝕜' →L[𝕜] 𝕜')
is a bounded bilinear map.
Given a bounded bilinear map f
, the map associating to a point p
the derivative of f
at
p
is itself a bounded linear map.