λ A
1/λ A
A X
X = C[a, b] K ∈ C([a, b] × [a, b])
X = L
2
[a, b] K ∈ L
2
((a, b) × (a, b))
X
(ϕ, ψ) =
Z
b
a
ϕ(x)ψ(x)dx.
A
∗
: X → X
A : X → X
(Aϕ, ψ) = (ϕ, A
∗
ψ) ∀ϕ, ψ ∈ X.
A
∗
A
[A
∗
ψ](y) =
Z
b
a
K(x, y)ψ(x)dx.
ϕ − λAϕ = f,
ψ − λA
∗
ψ = f
∗
,
ϕ − λAϕ = 0,
ψ − λA
∗
ψ = 0,
A
λ
m > 0
ϕ
1
, ϕ
2
, ..., ϕ
m
ψ
1
, ψ
2
, ..., ψ
m
f
f
∗
(f, ψ
i
) =
Z
b
a
f(x)ψ
i
(x)dx = 0,