Linear functions are analytic #
In this file we prove that a continuous_linear_map
defines an analytic function with
the formal power series f x = f a + f (x - a)
.
@[simp]
noncomputable
def
continuous_linear_map.fpower_series
{π : Type u_1}
[nontrivially_normed_field π]
{E : Type u_2}
[normed_add_comm_group E]
[normed_space π E]
{F : Type u_3}
[normed_add_comm_group F]
[normed_space π F]
(f : E βL[π] F)
(x : E) :
formal_multilinear_series π E F
Formal power series of a continuous linear map f : E βL[π] F
at x : E
:
f y = f x + f (y - x)
.
Equations
- f.fpower_series x n.succ.succ = 0
- f.fpower_series x 1 = β((continuous_multilinear_curry_fin1 π E F).symm) f
- f.fpower_series x 0 = continuous_multilinear_map.curry0 π E (βf x)
@[simp]
theorem
continuous_linear_map.fpower_series_apply_add_two
{π : Type u_1}
[nontrivially_normed_field π]
{E : Type u_2}
[normed_add_comm_group E]
[normed_space π E]
{F : Type u_3}
[normed_add_comm_group F]
[normed_space π F]
(f : E βL[π] F)
(x : E)
(n : β) :
f.fpower_series x (n + 2) = 0
@[simp]
theorem
continuous_linear_map.fpower_series_radius
{π : Type u_1}
[nontrivially_normed_field π]
{E : Type u_2}
[normed_add_comm_group E]
[normed_space π E]
{F : Type u_3}
[normed_add_comm_group F]
[normed_space π F]
(f : E βL[π] F)
(x : E) :
(f.fpower_series x).radius = β€
@[protected]
theorem
continuous_linear_map.has_fpower_series_on_ball
{π : Type u_1}
[nontrivially_normed_field π]
{E : Type u_2}
[normed_add_comm_group E]
[normed_space π E]
{F : Type u_3}
[normed_add_comm_group F]
[normed_space π F]
(f : E βL[π] F)
(x : E) :
has_fpower_series_on_ball βf (f.fpower_series x) x β€
@[protected]
theorem
continuous_linear_map.has_fpower_series_at
{π : Type u_1}
[nontrivially_normed_field π]
{E : Type u_2}
[normed_add_comm_group E]
[normed_space π E]
{F : Type u_3}
[normed_add_comm_group F]
[normed_space π F]
(f : E βL[π] F)
(x : E) :
has_fpower_series_at βf (f.fpower_series x) x
@[protected]
theorem
continuous_linear_map.analytic_at
{π : Type u_1}
[nontrivially_normed_field π]
{E : Type u_2}
[normed_add_comm_group E]
[normed_space π E]
{F : Type u_3}
[normed_add_comm_group F]
[normed_space π F]
(f : E βL[π] F)
(x : E) :
analytic_at π βf x
noncomputable
def
continuous_linear_map.uncurry_bilinear
{π : Type u_1}
[nontrivially_normed_field π]
{E : Type u_2}
[normed_add_comm_group E]
[normed_space π E]
{F : Type u_3}
[normed_add_comm_group F]
[normed_space π F]
{G : Type u_4}
[normed_add_comm_group G]
[normed_space π G]
(f : E βL[π] F βL[π] G) :
continuous_multilinear_map π (Ξ» (i : fin 2), E Γ F) G
Reinterpret a bilinear map f : E βL[π] F βL[π] G
as a multilinear map
(E Γ F) [Γ2]βL[π] G
. This multilinear map is the second term in the formal
multilinear series expansion of uncurry f
. It is given by
f.uncurry_bilinear ![(x, y), (x', y')] = f x y'
.
Equations
- f.uncurry_bilinear = (β((continuous_multilinear_curry_fin1 π (E Γ F) G).symm).comp (f.bilinear_comp (continuous_linear_map.fst π E F) (continuous_linear_map.snd π E F))).uncurry_left
@[simp]
theorem
continuous_linear_map.uncurry_bilinear_apply
{π : Type u_1}
[nontrivially_normed_field π]
{E : Type u_2}
[normed_add_comm_group E]
[normed_space π E]
{F : Type u_3}
[normed_add_comm_group F]
[normed_space π F]
{G : Type u_4}
[normed_add_comm_group G]
[normed_space π G]
(f : E βL[π] F βL[π] G)
(m : fin 2 β E Γ F) :
@[simp]
noncomputable
def
continuous_linear_map.fpower_series_bilinear
{π : Type u_1}
[nontrivially_normed_field π]
{E : Type u_2}
[normed_add_comm_group E]
[normed_space π E]
{F : Type u_3}
[normed_add_comm_group F]
[normed_space π F]
{G : Type u_4}
[normed_add_comm_group G]
[normed_space π G]
(f : E βL[π] F βL[π] G)
(x : E Γ F) :
formal_multilinear_series π (E Γ F) G
Formal multilinear series expansion of a bilinear function f : E βL[π] F βL[π] G
.
Equations
- f.fpower_series_bilinear x n.succ.succ.succ = 0
- f.fpower_series_bilinear x 2 = f.uncurry_bilinear
- f.fpower_series_bilinear x 1 = β((continuous_multilinear_curry_fin1 π (E Γ F) G).symm) (β(f.derivβ) x)
- f.fpower_series_bilinear x 0 = continuous_multilinear_map.curry0 π (E Γ F) (β(βf x.fst) x.snd)
@[simp]
theorem
continuous_linear_map.fpower_series_bilinear_radius
{π : Type u_1}
[nontrivially_normed_field π]
{E : Type u_2}
[normed_add_comm_group E]
[normed_space π E]
{F : Type u_3}
[normed_add_comm_group F]
[normed_space π F]
{G : Type u_4}
[normed_add_comm_group G]
[normed_space π G]
(f : E βL[π] F βL[π] G)
(x : E Γ F) :
(f.fpower_series_bilinear x).radius = β€
@[protected]
theorem
continuous_linear_map.has_fpower_series_on_ball_bilinear
{π : Type u_1}
[nontrivially_normed_field π]
{E : Type u_2}
[normed_add_comm_group E]
[normed_space π E]
{F : Type u_3}
[normed_add_comm_group F]
[normed_space π F]
{G : Type u_4}
[normed_add_comm_group G]
[normed_space π G]
(f : E βL[π] F βL[π] G)
(x : E Γ F) :
has_fpower_series_on_ball (Ξ» (x : E Γ F), β(βf x.fst) x.snd) (f.fpower_series_bilinear x) x β€
@[protected]
theorem
continuous_linear_map.has_fpower_series_at_bilinear
{π : Type u_1}
[nontrivially_normed_field π]
{E : Type u_2}
[normed_add_comm_group E]
[normed_space π E]
{F : Type u_3}
[normed_add_comm_group F]
[normed_space π F]
{G : Type u_4}
[normed_add_comm_group G]
[normed_space π G]
(f : E βL[π] F βL[π] G)
(x : E Γ F) :
has_fpower_series_at (Ξ» (x : E Γ F), β(βf x.fst) x.snd) (f.fpower_series_bilinear x) x
@[protected]
theorem
continuous_linear_map.analytic_at_bilinear
{π : Type u_1}
[nontrivially_normed_field π]
{E : Type u_2}
[normed_add_comm_group E]
[normed_space π E]
{F : Type u_3}
[normed_add_comm_group F]
[normed_space π F]
{G : Type u_4}
[normed_add_comm_group G]
[normed_space π G]
(f : E βL[π] F βL[π] G)
(x : E Γ F) :