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Lineáris transzformációk invariáns alterei

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V F A V V<br />

M A <br />

v ∈ M A(v) M A(M) ⊆ M.<br />

M<br />

V <br />

w A(w) M w M <br />

M M <br />

A A <br />

A <br />

A <br />

M A V A <br />

M <br />

V = {x1, . . . , xr, xr+1, . . . , xn} V {x1, . . . , xr}<br />

M A <br />

AV =<br />

A11 A12<br />

0 A22<br />

A11 A M r × r {x1, . . . , xr}<br />

0 n − r × r A12, A22 r × n − r <br />

n − r × n − r N = (xr+1, . . . , xn) A<br />

A12 <br />

<br />

<br />

A11<br />

AV =<br />

0<br />

0<br />

A22<br />

<br />

A11 A22 <br />

M A <br />

A V A M <br />

N (M, N) <br />

A<br />

A <br />

ker(A) (A) V <br />

A <br />

v ∈ V {v, A(v), A2 (v), . . .}<br />

(v, A) V n<br />

{v, A(v), A2 (v), . . . An (v)} <br />

n + 1 <br />

Ak (v) (1 ≤ k ≤ n) v, A(v), . . . , Ak−1 (v) <br />

m Ak+m (v) <br />

v, A(v), . . . , Ak−1 (v) m <br />

<br />

<br />

A k k−1 <br />

(v) = αiA i (v) ,<br />

i=0


A k+1 k−1 <br />

(v) = αiA i+1 k−2 <br />

(v) = αiA i+1 (v) + αk−1<br />

i=0<br />

i=0<br />

<br />

k−1<br />

<br />

αiA i <br />

(v) =<br />

i=0<br />

k−1<br />

= αk−1α0v + (αi−1 + αk−1αi)A i (v) ,<br />

i=1<br />

m = 1 m − 1 ≥ 1<br />

A k+m−1 k−1 <br />

(v) = βiA i (v) ,<br />

<br />

i=0<br />

A k+m k−1 <br />

(v) = βiA i+1 k−2 <br />

(v) = βiA i+1 (v) + βk−1<br />

i=0<br />

i=0<br />

<br />

k−1<br />

k−1<br />

= βk−1β0v + (βi−1 + βk−1αi)A i (v) ,<br />

i=1<br />

<br />

αiA i <br />

(v) =<br />

A k+m (v) v, A(v), . . . , A k−1 (v) <br />

(v, A) = v, A(v), . . . , A k−1 (v) <br />

(v, A) <br />

(v, A) A v <br />

<br />

<br />

<br />

A ∈ L(V ) <br />

p(A) = α0A 0 + α1A + · · · + αkA k<br />

V A<br />

p(A) <br />

p(A) <br />

A v ∈ ker(p(A)) p(A)(v) = 0 <br />

p(A)(A(v)) = A(p(A)(v)) = A(0) = 0 A(v) ∈ ker(p(A)) <br />

v ∈ (p(A)) w ∈ V p(A)(w) = v <br />

p(A)(A(w)) = A(p(A)(w)) = A(v) A(v) ∈ (p(A)) <br />

<br />

<br />

<br />

p(t) ∈ F[t] F → F <br />

<br />

<br />

i=0


F F V <br />

L(V ) F dim V × dim V <br />

F dim V ×dim V L(V ) <br />

<br />

dim V ×dim V<br />

Φ : L(V ) → F<br />

A ∈ L(V ) <br />

<br />

p(t) = α0 + α1t + · · · + αnt n<br />

V <br />

p(A) = α0A 0 + α1A + · · · + αnA n<br />

A ∈ F dim V ×dim V <br />

p(A) = α0A 0 + α1A + · · · + αnA n dim V ×dim V<br />

∈ F<br />

p(A) A <br />

p(A) A<br />

<br />

A <br />

p(t) <br />

A A p(A) <br />

<br />

<br />

<br />

<br />

p(t) + q(t) = r(t) p(t) · q(t) = s(t) ,<br />

p(A) + q(A) = r(A) p(A) · q(A) = s(A) ,<br />

p(A) + q(A) = r(A) p(A) · q(A) = s(A).<br />

<br />

<br />

A A p(t) <br />

p(A) = 0 p(A) = 0). <br />

p(t) <br />

<br />

<br />

<br />

B p(t) <br />

p(B −1 AB) = B −1 p(A)B .


V n F A ∈ L(V ) <br />

F[t] dim L(V ) = n 2 <br />

A 0 = I, A, . . . , A n2<br />

n 2 +1 <br />

<br />

α0A 0 + α1A + · · · + αn2A n2<br />

= 0 .<br />

<br />

p(t) = α0 + α1t + · · · + αn2t n2<br />

A A <br />

p(t) = α0 + α1t + · · · + αmtm m 1/αm · p(t)<br />

m <br />

<br />

A<br />

A <br />

<br />

mA(t) m ′ A<br />

A mA(t) − m ′ A (t) mA(t) − m ′ A<br />

(t) A <br />

mA(t) mA(t) <br />

(t) <br />

<br />

A <br />

A <br />

f(t) A <br />

f(A) = 0 <br />

f(t) = h(t)mA(t) + r(t) 0 ≤ deg r(t) < deg mA(t).<br />

A <br />

0 = f(A) = h(A)mA(A) + r(A) = r(A) ,<br />

r(t) ≡ 0 , A mA(t)<br />

<br />


V n F <br />

A ∈ L(V ) mA(t) ∈ F[t] <br />

k V k A<br />

<br />

p(t) k A <br />

ker(p(A)) k A k A <br />

<br />

mA(t) A mA(t) =<br />

p(t)q(t) p(t) k <br />

ker(p(A)) A v = 0 <br />

ker(p(A)) q(t) A<br />

(v, A) k A ker(p(A))<br />

V {v, A(v), . . . A n (v)} <br />

m(≤ n) <br />

{v, A(v), . . . , A m−1 (v)} <br />

A m (v) v, A(v), . . . , A m−1 (v) <br />

<br />

A m (v) = ε0v + ε1A(v) + · · · + εm−1A m−1 (v)<br />

<br />

s(t) = −ε0 − ε1t − · · · − εm−1t m−1 + t m<br />

s(A)(v) = 0 , m <br />

m A <br />

v v ker(p(A))<br />

p(A)(v) = 0 , <br />

m = deg s(t) ≤ deg p(t) = k .<br />

p(t) s(t) <br />

<br />

<br />

p(t) = h(t)s(t) + r(t) 0 ≤ deg r(t) < deg s(t) = m ,<br />

p(A) = h(A)s(A) + r(A) .<br />

0 = p(A)(v) = h(A)s(A)(v) + r(A)(v) = r(A)(v) ,<br />

r(t) ≡ 0 p(t) = h(t)s(t) . <br />

p(t) h(t) s(t) p(t)<br />

k = m . (v, A) = v, A(v), . . . , A k−1 (v) <br />

k A<br />

ker(p(A)) v w <br />

(v, A) (w, A) <br />

x ∈ (v, A) (w, A)


{x, A(x), . . . , A k−1 (x)}<br />

(v, A) (w, A)<br />

A <br />

dim(v, A) = dim(w, A) = k<br />

{x, A(x), . . . , A k−1 (x)} (v, A)<br />

(w, A) <br />

(v, A) = (w, A) .<br />

ker(p(A)) <br />

v1 ∈ ker(p(A)) (v1, A)<br />

ker(p(A)) \ (v1, A) v2 <br />

(v1, A) ⊕ (v2, A) 2 · k ker(p(A))<br />

<br />

<br />

v3 ∈ ker(p(A)) \ (v1, A) ⊕ (v2, A)<br />

(v1, A) ⊕ (v2, A) ⊕ (v3, A)<br />

ker(p(A)) <br />

r ≥ 1 <br />

ker(p(A)) \ (v1, A) ⊕ · · · ⊕ (vr, A) = ∅ ,<br />

<br />

x ∈ ker(p(A)) x = 0 (y, A) ⊆<br />

ker(p(A)) (x, A) = (y, A) <br />

<br />

vi ∈ (v1, A) ⊕ · · · ⊕ (vi−1, A) ,<br />

(vi, A) (v1, A) ⊕ · · · ⊕ (vi−1, A) = {0} .<br />

x <br />

x ∈ (vi, A) (v1, A) ⊕ · · · ⊕ (vi−1, A),<br />

(vi, A) = (x, A) x = i−1 j=1 wj,<br />

(vj, A) j = (1, . . . , i − 1). <br />

A<br />

wj ∈<br />

t i−1<br />

(x) = A t (wj) ∈ (v1, A) ⊕ · · · ⊕ (vi−1, A)<br />

j=1<br />

t(= 1, . . . , k − 1) <br />

vi ∈ (x, A) ⊆ (v1, A) ⊕ · · · ⊕ (vi−1, A),


vi ∈ (v1, A)⊕· · ·⊕(vi−1, A) <br />

✷<br />

<br />

<br />

<br />

2 <br />

1 <br />

<br />

1 <br />

F V A ∈ L(V ) <br />

A mA(t) λ ∈ F t − λ <br />

mA(t) ker(A−λI) 1<br />

A 1 A <br />

<br />

A F <br />

A λ A ker(A − λI)<br />

s A <br />

ker(A − λI) λ <br />

ker(A − λI) λ <br />

<br />

<br />

A F V <br />

<br />

F F <br />

A ∈ L(V ) (V = {0}) <br />

<br />

s <br />

A(s) = (A − λI)(s) + λs = λs<br />

<br />

A−λI V <br />

v ker(A − λI) mA(t) t − λ ∈ F[t] <br />

<br />

mA(t) = q(t)(t − λ) + γ<br />

0 <br />

mA(A) = q(A)(A − λI) + γI


0 = mA(A)(v) = q(A)(A − λI)(v) + γI(v) = γv ,<br />

γ = 0 t−λ mA(t) mA(λ) = 0 ,<br />

λ <br />

<br />

<br />

V F A A <br />

λ ∈ F λ <br />

A A − λI ∈ L(V ) <br />

<br />

<br />

0 <br />

<br />

<br />

<br />

A ∈ L(V ) λ <br />

<br />

M A V M ◦ A ′<br />

V ′<br />

A ∈ L(V ) λ <br />

p(t) ∈ F[t] p(A) p(λ) <br />

A A −1 1<br />

λ .<br />

<br />

<br />

(A − λI) ′<br />

= A ′<br />

− λI ′<br />

,<br />

A − λI A ′<br />

− λI ′<br />

<br />

v M y M ◦<br />

<br />

[v, A ′ (y)] = [A(v), y],<br />

A(v) ∈ M, A ′ (y) ∈ M ◦ A ′ (y) ∈ M ◦ , A(v) ∈ M<br />

<br />

A λ <br />

s(= 0) ∈ V A(s) = λs . A2 (s) =<br />

A(A(s)) = A(λs) = λA(s) = λ2s , <br />

k Ak (s) = λks <br />

p(t) = α0 + α1t + · · · + αktk ∈ F[t] <br />

p(A)(s) = (α0I + α1A + · · · + αkA k )(s) = α0s + α1A(s) + · · · + αkA k (s) =


α0s + α1λs + · · · + αkλ k s = p(λ)s,<br />

p(λ) p(A) <br />

<br />

s = A −1 (A(s)) = A −1 (λs) = λA −1 (s)<br />

λ = 0 <br />

A −1 (s) = 1<br />

s .<br />

λ<br />

<br />

<br />

<br />

<br />

3 V A <br />

V = {v1, v2, v3} <br />

A(v1) = v2 + v3, A(v2) = v1 + v3, A(v3) = v1 + v2 <br />

<br />

A A − λI V <br />

<br />

⎡<br />

A = ⎣<br />

0 1 1<br />

1 0 1<br />

1 1 0<br />

⎤<br />

⎡<br />

⎦ A − λE = ⎣<br />

−λ 1 1<br />

1 −λ 1<br />

1 1 −λ<br />

λ A − λE <br />

<br />

λ <br />

A − λE <br />

ξ1, ξ2, ξ3 <br />

ξ1 ξ2 ξ3<br />

v1 −λ 1 1<br />

v2 −λ 1<br />

v3 1 1 −λ<br />

−→<br />

λ = −1 <br />

⎡<br />

ξ1<br />

⎢<br />

⎣ ξ2<br />

⎤ ⎡<br />

−1<br />

⎥ ⎢<br />

⎦ = ⎣ 1<br />

⎤<br />

−1<br />

⎥<br />

0 ⎦ ·<br />

0 1<br />

ξ3<br />

ξ2<br />

ξ3<br />

v1 1 − λ 2 1 + λ<br />

ξ1 −λ 1<br />

v3 1 + λ −λ − 1<br />

τ2<br />

τ2, τ3 <br />

<br />

s1 =<br />

⎡<br />

⎢<br />

⎣<br />

−1<br />

1<br />

0<br />

⎤<br />

⎡<br />

τ3<br />

⎥<br />

⎢<br />

⎦ s2 = ⎣<br />

<br />

−1<br />

0<br />

1<br />

⎤<br />

⎥<br />

⎦<br />

⎤<br />


λ = −1 <br />

<br />

λ = −1 <br />

ξ3<br />

v1 2 + λ − λ 2<br />

ξ1<br />

ξ2<br />

1 − λ<br />

λ = 2 <br />

⎡ ⎤ ⎡ ⎤<br />

ξ1 1<br />

⎢ ⎥ ⎢ ⎥<br />

⎣ ξ2 ⎦ = ⎣ 1 ⎦ · τ3 (τ3 = 0) .<br />

ξ3 1<br />

λ = 2 <br />

⎡ ⎤<br />

1<br />

⎢ ⎥<br />

s3 = ⎣ 1 ⎦ .<br />

1<br />

A <br />

<br />

S = {s1 = −v1 + v2, s2 = −v1 + v3, s3 = v1 + v2 + v3}<br />

A(s1) = −s1, A(s2) = −s2 A(s3) = 2 · s3 , <br />

⎡<br />

⎤<br />

−1 0 0<br />

AS = ⎣ 0 −1 0 ⎦<br />

0 0 2<br />

A <br />

<br />

<br />

<br />

<br />

<br />

n F V A ∈ L(V ) <br />

S = {s1, . . . , sn} A<br />

S <br />

<br />

<br />

λ1, . . . , λn . <br />

−1<br />

A(si) = λisi (i = 1, . . . , n) ,


⎡<br />

⎢<br />

A(si)S = ⎢<br />

⎣<br />

λi<br />

⎥<br />

0 ⎥<br />

<br />

⎥<br />

⎦<br />

0<br />

i λi A <br />

AS i A(si)S i(= 1, . . . , n)<br />

AS =<br />

⎡<br />

⎢ ⎢ ⎣<br />

0<br />

<br />

0<br />

⎤<br />

⎥ ,<br />

λ1 0 . . . 0<br />

0 λ2 . . . 0<br />

<br />

<br />

<br />

0 0 . . . λn<br />

<br />

<br />

<br />

<br />

<br />

−1 <br />

<br />

<br />

<br />

<br />

V A λ1, . . . , λk <br />

s1, . . . , sk <br />

<br />

<br />

k = 1 <br />

λ1, . . . , λk−1 <br />

{s1, . . . , sk−1} <br />

λk sk <br />

<br />

k−1 <br />

(a) sk =<br />

i=1<br />

αisi ,<br />

{s1, . . . , sk−1, sk} <br />

A sk <br />

<br />

⎤<br />

⎥<br />


k−1 <br />

k−1 <br />

(b) λksk = A(sk) = αiA(si) =<br />

i=1<br />

i=1<br />

αiλisi .<br />

λk <br />

k−1 <br />

0 = αi(λi − λk)si<br />

i=1<br />

sk = 0 αi <br />

λi −<br />

λk, (i = 1, . . . , k − 1) <br />

{s1, . . . , sk−1} <br />

{s1, . . . , sk−1, sk} <br />

<br />

<br />

n V A n <br />

A <br />

<br />

<br />

<br />

<br />

A <br />

A <br />

A <br />

A <br />

<br />

<br />

V F A ∈ L(V ) <br />

A mA(t) p(t) <br />

q(t) <br />

V = ker p(A) ⊕ ker q(A) ,<br />

V A <br />

p(t) ker p(A) A<br />

V ker p(A) ker q(A)<br />

V <br />

ker p(A) ker q(A)


u ∈ ker p(A) ∩ ker q(A). p(t) q(t) <br />

1 1 = f(t)p(t)+g(t)q(t) <br />

A <br />

<br />

I(= 1 · A 0 ) = f(A)p(A) + g(A)q(A) .<br />

u = I(u) = f(A)p(A)(u) + g(A)q(A)(u) = 0,<br />

u ker p(A) ker q(A)<br />

V ker p(A) <br />

ker q(A) <br />

I(= 1 · A 0 ) = f(A)p(A) + g(A)q(A)<br />

v ∈ V <br />

v = I(v) = (f(A)p(A))(v) + (g(A)q(A))(v) <br />

q(A)(f(A)p(A)(v)) = f(A)(mA(A)(v)) = 0 <br />

p(A)(g(A)q(A)(v)) = g(A)(mA(A)(v)) = 0 , f(A)p(A)(v) ∈<br />

ker q(A) g(A)q(A)(v) ∈ ker p(A) , v <br />

<br />

✷<br />

A V <br />

ker p(A) ker q(A) V =<br />

{v1, . . . , vr} ker p(A) W = {w1, . . . , ws} ker q(A) <br />

A V {v1, . . . , vr, w1, . . . , ws} <br />

A =<br />

A1 0<br />

0 A2<br />

A1 r × r A2 s × s <br />

A A A1 A2 <br />

A <br />

<br />

<br />

A(vi) =<br />

A(wk) =<br />

<br />

r<br />

αijvj (i = 1, . . . , r)<br />

j=1<br />

s<br />

βkℓwℓ (ℓ = 1, . . . , s) ,<br />

ker p(A) ker q(A) A <br />

<br />

ℓ=1


mA(t) = p(t)q(t) A ∈ L(V ) <br />

p(t) A <br />

ker p(A) q(t) A<br />

ker q(A) <br />

A ker p(A) p(t) <br />

s(t) s(t)q(t)<br />

A s(t)q(t) <br />

mA(t) <br />

v ∈ V <br />

v = x + y (x ∈ ker p(A) , y ∈ ker q(A))<br />

s(A)q(A) <br />

v <br />

(s(A)q(A)(v) = s(A)q(A)(x) + s(A)q(A)(y) = 0 ,<br />

s(A)(x) = 0 q(A)(y) = 0 <br />

v ∈ V s(A)q(A) = 0 .<br />

q(t) A <br />

ker q(A) ✷<br />

<br />

<br />

A ∈ L(V ) <br />

mA(t) = p1(t) · p2(t) · · · · · pr(t)<br />

V <br />

A<br />

ker p1(A), ker p2(A), . . . , ker pr(A)<br />

<br />

V = ker p1(A) ⊕ ker p2(A) ⊕ · · · ⊕ ker pr(A)<br />

<br />

A ker pi(A) <br />

<br />

⎡<br />

A1 0 . . . 0<br />

⎢ 0 A2 . . . 0<br />

A = ⎢<br />

⎣<br />

<br />

<br />

<br />

0 0 . . . Ar<br />

Ai A ker pi(A) <br />

<br />

⎤<br />

⎥<br />


F[t] F <br />

V A mA(t) <br />

<br />

<br />

mA(t) = (p1(t)) m1 · · · · · (pr(t)) mr<br />

V <br />

<br />

V = ker p m1<br />

1 (A) ⊕ · · · ⊕ ker pmr r (A)<br />

A <br />

<br />

ker p mi<br />

i (A) = Vi (i = 1, . . . , r) ,<br />

pi(A) Vi Bi Bi Vi <br />

mi <br />

<br />

B m<br />

B m = 0 B <br />

B m <br />

pi(t) ki Vi <br />

ki · mi . <br />

<br />

A ∈ L(V ) p m (t) , p(t)<br />

k V k · m .<br />

A p m (t) , v ∈ V <br />

p m−1 (A)(v) = 0 . <br />

v, A(v), . . . , Ak−1 (v),<br />

p(A)(v), (p(A)A)(v), . . . , (p(A)Ak−1 )(v),<br />

<br />

p m−1 (A)(v), (p m−1 (A)A)(v), . . . , (p m−1 (A)A k−1 )(v)<br />

<br />

m−1 <br />

<br />

i=0 j=0<br />

<br />

<br />

k−1<br />

βij(p i (A)A j )(v) = 0 <br />

ℓ(≥ 0) <br />

j βℓj = 0 . <br />

pm−ℓ−1 (A) <br />

p m−ℓ−1 ⎛<br />

m−1 k−1 <br />

(A) ⎝<br />

i=0 j=0<br />

βij(p i (A)A j )(v)<br />

⎞<br />

k−1 <br />

⎠ =<br />

j=0<br />

βℓj(p m−1 (A)A j )(v) = 0 ,


i < ℓ βij = 0, i > ℓ p m−ℓ+i−1 (A) = 0 j<br />

βℓj = 0 . p m−1 (A)(v) = 0 <br />

p(A) p(t) k <br />

<br />

p m−1 (A)(v), A p m−1 (A)(v) , . . . , A k−1 p m−1 (A)(v) <br />

<br />

<br />

βij <br />

V m · k <br />

m · k . <br />

<br />

n V A ∈ L(V ) <br />

n 2 <br />

<br />

<br />

V n A <br />

n<br />

A <br />

<br />

mA(t) = (p1(t)) m1 · · · · · (pr(t)) mr<br />

V <br />

V = ker(p m1<br />

1 (A)) ⊕ · · · ⊕ ker(pmr r (A))<br />

deg pi(t) = ki (i = 1, . . . , r) <br />

<br />

deg mA(t) = m1 · k1 + · · · + mr · kr ≤<br />

≤ dim ker(p m1<br />

1 (A)) + · · · + dim ker(pmr r (A)) = dim V = n .<br />

<br />

<br />

<br />

n V n <br />

<br />

<br />

<br />

3 V A <br />

V = {v1, v2, v3} A(v1) = v1 +<br />

v2 + v3, A(v2) = v1 + v2 A(v3) = v1 A


A <br />

<br />

L(V ) 3 × 3 <br />

A V <br />

<br />

⎡<br />

A 0 = ⎣<br />

⎡<br />

A 2 = ⎣<br />

1 0 0<br />

0 1 0<br />

0 0 1<br />

3 2 1<br />

2 2 1<br />

1 1 1<br />

⎤<br />

⎡<br />

⎦ A = ⎣<br />

⎤<br />

⎡<br />

⎦ A 3 = ⎣<br />

1 1 1<br />

1 1 0<br />

1 0 0<br />

6 5 3<br />

5 4 2<br />

3 2 1<br />

<br />

M3×3 = {Eij (i, j = 1, 2, 3)} <br />

Eij 3 × 3 i j 1 <br />

<br />

<br />

<br />

A 0 A A 2 A 3<br />

E11 1 1 3 6<br />

E12 0 1 2 5<br />

E13 0 1 1 3<br />

E21 0 1 2 5<br />

E22 1 1 2 4<br />

E23 0 0 1 2<br />

E31 0 1 1 3<br />

E32 0 0 1 2<br />

E33 0 1 1<br />

A 2 A 3<br />

E11 1 2<br />

E12 1 2<br />

E13 0 0<br />

E21 1 2<br />

E22 0 0<br />

E23 2<br />

A 1 3<br />

E32 1 2<br />

A 0 1 1<br />

→<br />

→<br />

⎤<br />

⎦<br />

⎤<br />

⎦<br />

A A 2 A 3<br />

E11 1 2 5<br />

E12 1 2 5<br />

E13 1 1 3<br />

E21 1 2 5<br />

E22 1 1 3<br />

E23 0 1 2<br />

E31 1 3<br />

E32 0 1 2<br />

A 0 0 1 1<br />

A 3<br />

E11 0<br />

E12 0<br />

E13 0<br />

E21 0<br />

E22 0<br />

A2 2<br />

A 1<br />

E32 0<br />

A0 −1<br />

A 3 = 2A 2 +A−A 0 , <br />

A 3 − 2A 2 − A + A 0 = 0 , mA(t) =<br />

t 3 − 2t 2 − t + 1 . ✷<br />


V F A <br />

v ∈ V pv(t) ∈ F[t] <br />

pv(A)(v) = 0 . pv(t) A mA(t) <br />

<br />

<br />

mA(t) = q(t)pv(t) + r(t) 0 ≤ deg r(t) < deg pv(t) .<br />

A <br />

mA(A) = q(A)pv(A) + r(A)<br />

A mA(A) v<br />

<br />

0 = mA(A)(v) = q(A)pv(A)(v) + r(A)(v) = r(A)(v) ,<br />

pv(t) <br />

r(t) ≡ 0 , ✷<br />

<br />

F V V = {v1, . . . , vn} A ∈ L(V )<br />

vi ∈ V pi(t) ∈ F[t] <br />

pi(A)(vi) = 0 . A mA(t) <br />

p1(t), . . . , pn(t) <br />

k(t) pi(t) (i = 1 . . . , n) <br />

v ∈ V <br />

<br />

v = ε1v1 + · · · + εnvn ,<br />

k(A)(v) = ε1k(A)(v1) + · · · + εnk(A)(vn) = 0 ,<br />

i(= 1, . . . , n)<br />

k(t) = qi(t)pi(t) ,


k(A)(vi) = qi(A)pi(A)(vi) = 0 .<br />

A k(t) pi(t) mA(t)<br />

k(t) mA(t) <br />

A<br />

mA(t) | k(t) <br />

k(t) = mA(t) , ✷<br />

<br />

<br />

<br />

V 3 V = {v1, v2, v3} <br />

A A(v1) = v1 + 2v2, A(v2) = v1 − v2 <br />

A(v3) = −v1 + v3 A <br />

v1 <br />

A <br />

A 2 (v1) = A(v1) + 2A(v2) = v1 + 2v2 + 2(v1 − v2) = 3v1 ,<br />

<br />

p1(t) = t 2 − 3 .<br />

V A, A 2 p1(A) = A 2 − 3I <br />

<br />

⎡<br />

A = ⎣<br />

1 1 −1<br />

2 −1 0<br />

0 0 1<br />

⎤<br />

⎡<br />

⎦ A 2 = ⎣<br />

⎡<br />

A 2 − 3E = ⎣<br />

0 0 −2<br />

0 0 −2<br />

0 0 −2<br />

3 0 −2<br />

0 3 −2<br />

0 0 1<br />

p2(t) = p1(t) p1(A)(v3) = 0 . <br />

A 2 (v3) = −2v1 − 2v2 + v3. <br />

A 3 (v3) = −2A(v1) − 2A(v2) + A(v3) =<br />

−2(v1 + 2v2) − 2(v1 − v2) + (−v1 + v3) = −5v1 − 2v2 + v3 .<br />

V p3(t)<br />

v3 <br />

<br />

Av3 A 2 v3 A 3 v3<br />

v1 −1 −2 −5<br />

v2 0 −2<br />

v3 1 1 1<br />

→<br />

⎤<br />

⎦<br />

Av3 A 3 v3<br />

v1 −3<br />

A 2 (v3) 0 1<br />

v3 1 0<br />

→<br />

⎤<br />

⎦<br />

A 3 v3<br />

A(v3) 3<br />

A 2 (v3) 1<br />

v3<br />

−3


A 3 (v3) = A 2 (v3) + 3A(v3) − 3v3 , <br />

A 3 (v3) − A 2 (v3) − 3A(v3) + 3v3 , <br />

p3(t) = t 3 − t 2 − 3t + 3 = (t 2 − 3)(t − 1) .<br />

p3(t) <br />

A <br />

<br />

<br />

<br />

<br />

<br />

<br />

v3 <br />

<br />

<br />

<br />

<br />

<br />

<br />

<br />

V A ∈<br />

L(V ) A<br />

<br />

<br />

<br />

A n V <br />

M0, M1, . . . , Mn A V <br />

dim Mi = i, (i = 0, 1, . . . , n),<br />

{0} = M0 ⊂ M1 ⊂ . . . ⊂ Mn−1 ⊂ Mn = V .<br />

V V<br />

0, 1, n−1<br />

dim V = n. V <br />

A <br />

<br />

V ′ 1 A ′ M ′ M ′ <br />

V n − 1 Mn−1 = M ′◦ .<br />

Mn−1 A A Mn−1


Mn−1<br />

A M0, M1, . . . , Mn−2 <br />

dim Mi = i (i = 0, 1, . . . , n − 2), <br />

M0 ⊂ M1 ⊂ . . . ⊂ Mn−2 ⊂ Mn−1. Mn = V <br />

A <br />

<br />

V x1 M1 <br />

M1 ⊂ M2 x2 ∈ M2 <br />

{x1, x2} M2 x3 ∈ M3 {x1, x2, x3}<br />

M3 V = {x1, x2, . . . , xn} <br />

V i (1 ≤ i ≤ n) {x1, . . . , xi}<br />

Mi i Mi A A(xi) ∈<br />

({x1, . . . , xi}). A V <br />

⎡<br />

⎢<br />

AV = ⎢<br />

⎣<br />

α11 α12 α13 . . . α1n<br />

0 α22 α23 . . . α2n<br />

0 0 α33 . . . α3n<br />

<br />

0 0 0 . . . αnn<br />

<br />

i (1 ≤ i ≤ n) A − αiiI <br />

Mi Mi−1 <br />

A A αii <br />

<br />

A p(t)<br />

m p(A) B <br />

A ker p m (A) m <br />

<br />

<br />

B m W <br />

v W B m−1 (v) = 0 , <br />

{B m−1 (v), . . . , B(v), v}<br />

<br />

B W1 W W = (v, B) ⊕ W1 , <br />

W <br />

<br />

W v <br />

B m−1 (v) = 0 , B m − 1 <br />

⎤<br />

⎥<br />


{Bm−1 (v), . . . , B(v), v} <br />

<br />

m−1 <br />

i=0<br />

αiB i (v) = 0 .<br />

<br />

αj (0 ≤ j ≤ m − 1) <br />

B m−j−1<br />

<br />

m−1 <br />

αiB i <br />

(v) = αjB m−1 (v) = 0 ,<br />

i=0<br />

B m−1 (v) = 0 α0 = α1 = . . . = αm−1 = 0<br />

{B m−1 (v), . . . , B(v), v} <br />

<br />

B <br />

m = 1 , W v <br />

W W1 B<br />

W = (v) ⊕ W1 . m − 1 <br />

(B) W B <br />

B m−1 <br />

W0 B (B) = (B(v), B)⊕W0 . <br />

(B) <br />

{B m−1 (v), . . . , B(v)}<br />

W 0 = {w ∈ W | B(w) ∈ W0} . <br />

W 0 W B<br />

(v, B) ∪ W 0 W <br />

x ∈ W B(x) ∈ (B) , <br />

B(x) =<br />

m−1 <br />

i=1<br />

<br />

B(x) = B<br />

αiB i (v) + w, w ∈ W0<br />

m−2<br />

<br />

i=0<br />

αi+1B i (v)<br />

<br />

B<br />

<br />

x −<br />

m−2 <br />

i=0<br />

αi+1B i (v)<br />

W 0 <br />

m−2 <br />

x −<br />

i=0<br />

<br />

<br />

+ w<br />

= w .<br />

αi+1B i (v) ∈ W 0 ,


m−2<br />

i=0 αi+1B i (v) ∈ (v, B) , W x<br />

(v, B) W 0 <br />

(v, B) ∩ W 0 <br />

W 0 W1 <br />

x ∈ (v, B) ∩ W0, B(x) ∈ (B(v), B) ∩ W0 ,<br />

B(x) = 0 . x B m−1 (v) <br />

<br />

x ∈ (B(v), B) ∩ W0 = {0}<br />

x = 0 . <br />

(v, B) ∩ W0 = {0}.<br />

(v, B) ∩ W 0 W0 W 0 W 0 <br />

(v, B) ∩ W 0 V W0 W<br />

w1, . . . , wℓ <br />

<br />

W1 = (W ∪ {w1, . . . , wℓ}) .<br />

W = (v, B) ⊕ W1<br />

W1 B <br />

W0 ⊆ W1 ⊆ W 0 , W1 B<br />

W0 B <br />

˜v ∈ W <br />

(˜v, B) m W = (˜v, B) ⊕ W1 <br />

B W1 W1 <br />

(v, B) (˜v, B) m <br />

dim W1 dim W1 <br />

<br />

W1<br />

B m1(≤ m) <br />

W1 = (v1, B)⊕W2 W2 <br />

W3 <br />

Wr B (vr, B) <br />

<br />

<br />

B m W<br />

(m ≥)m1 ≥ . . . ≥ mr <br />

v0, v1, . . . , vr ∈ W <br />

Bm−1 (v0), . . . , B(v0), v0<br />

Bm1−1 (v1), . . . , B(v1), v1<br />

<br />

<br />

B mr−1 (vr), . . . , B(vr), vr


W <br />

W = (v0, B) ⊕ (v1, B) ⊕ · · · ⊕ (vr, B) .<br />

(m ≥)m1 ≥ . . . ≥ mr <br />

W B <br />

<br />

B B <br />

<br />

m−1, m1 −1, . . . , mr −1 1 <br />

0 <br />

<br />

V F <br />

F[t] <br />

A ∈ L(V ) <br />

<br />

mA(t) = (t − λ1) m1 · · · · · (t − λr) mr<br />

λ1, . . . , λr ∈ F . <br />

V = ker ((A − λ1I) m1 ) ⊕ · · · ⊕ ker ((A − λrI) mr )<br />

A − λiI <br />

Wi = ker((A − λiI) mi ) mi <br />

i(= 1, . . . , r) (mi0 ≥)mi1 ≥<br />

. . . ≥ mis vi0, vi1, . . . , vis ∈ Wi <br />

(A − λiI) mi0−1 (vi0), . . . , (A − λiI)(vi0), vi0<br />

(A − λiI) mi1−1 (vi1), . . . , (A − λiI)(vi1), vi1<br />

<br />

<br />

<br />

(A − λiI) mis−1 (vis),<br />

Wi <br />

. . . , (A − λiI)(vis), vis<br />

Wi = (vi0, (A − λiI)) ⊕ (vi1, (A − λiI)) ⊕ · · · ⊕ (vis, (A − λiI)) .<br />

(vij, (A − λiI)) (j = 0, . . . , s) <br />

A − λiI A <br />

A Wi Ai <br />

j(= 0, . . . , s)<br />

=<br />

A((A − λiI) k )(vij) =<br />

((A − λiI) k+1 )(vij) + λi((A − λiI) k (vij) 0 ≤ k < mij − 1,<br />

λi((A − λiI) k (vij) k = mij − 1


(A − λiI) mi0−1 (vi0), (A − λiI) mi1−1 (vi1), . . . , (A − λiI) mis−1 (vis)<br />

A λi ker(A − λiI)<br />

<br />

Ai λi <br />

mi0 − 1, mi1 − 1, . . . , mis − 1 <br />

0 <br />

<br />

⎡<br />

λi<br />

⎢<br />

0<br />

⎢ ⎢<br />

0<br />

⎢<br />

0<br />

⎢<br />

0<br />

⎢<br />

0<br />

⎢ ⎢<br />

Ai = ⎢ ⎢ 0<br />

⎢ 0<br />

⎢ 0<br />

⎢ 0<br />

⎢ ⎢<br />

⎣ 0<br />

1<br />

λi<br />

<br />

0<br />

0<br />

0<br />

0<br />

<br />

<br />

0<br />

0<br />

0<br />

0<br />

<br />

0<br />

0<br />

1<br />

<br />

· · ·<br />

· · ·<br />

· · ·<br />

· · ·<br />

<br />

<br />

· · ·<br />

· · ·<br />

· · ·<br />

· · ·<br />

<br />

· · ·<br />

· · ·<br />

· · ·<br />

<br />

λi<br />

0<br />

· · ·<br />

· · ·<br />

<br />

<br />

· · ·<br />

· · ·<br />

· · ·<br />

· · ·<br />

<br />

· · ·<br />

0<br />

0<br />

<br />

1<br />

λi<br />

0<br />

0<br />

<br />

<br />

0<br />

0<br />

0<br />

0<br />

<br />

0<br />

0<br />

0<br />

<br />

0<br />

0<br />

λi<br />

0<br />

<br />

<br />

0<br />

0<br />

0<br />

0<br />

<br />

0<br />

0<br />

0<br />

<br />

0<br />

0<br />

1<br />

λi<br />

<br />

<br />

0<br />

0<br />

0<br />

0<br />

<br />

0<br />

· · ·<br />

· · ·<br />

<br />

· · ·<br />

· · ·<br />

0<br />

1<br />

<br />

<br />

· · ·<br />

· · ·<br />

· · ·<br />

· · ·<br />

<br />

· · ·<br />

· · ·<br />

· · ·<br />

<br />

· · ·<br />

· · ·<br />

· · ·<br />

· · ·<br />

<br />

<br />

λi<br />

0<br />

· · ·<br />

· · ·<br />

<br />

· · ·<br />

0<br />

0<br />

<br />

0<br />

0<br />

0<br />

0<br />

<br />

<br />

1<br />

λi<br />

0<br />

0<br />

<br />

0<br />

0<br />

0<br />

<br />

0<br />

0<br />

0<br />

0<br />

<br />

<br />

0<br />

0<br />

λi<br />

0<br />

<br />

0<br />

0<br />

0<br />

<br />

0<br />

0<br />

0<br />

0<br />

<br />

<br />

0<br />

0<br />

1<br />

λi<br />

<br />

0<br />

· · ·<br />

· · ·<br />

<br />

· · ·<br />

· · ·<br />

· · ·<br />

· · ·<br />

<br />

<br />

· · ·<br />

· · ·<br />

0<br />

1<br />

<br />

· · ·<br />

· · ·<br />

· · ·<br />

<br />

· · ·<br />

· · ·<br />

· · ·<br />

· · ·<br />

<br />

<br />

· · ·<br />

· · ·<br />

· · ·<br />

· · ·<br />

<br />

λi<br />

0<br />

0<br />

<br />

0<br />

0<br />

0<br />

0<br />

<br />

<br />

0<br />

0<br />

0<br />

0<br />

<br />

1<br />

0 0 · · · · · · 0 0 0 · · · · · · 0 0 0 · · · 0 λi<br />

V (i = 1, . . . , r) Wi <br />

A A <br />

Ai (i = 1, . . . , r) <br />

λ1, . . . , λr λi dim ker((A − λiI) mi ) =<br />

mi0 + mi1 + · · · + mis <br />

<br />

A <br />

<br />

<br />

<br />

<br />

<br />

<br />

<br />

<br />

⎤<br />

⎥ .<br />

⎥<br />


3 W A <br />

W = {w1, w2, w3} <br />

<br />

⎡<br />

AW = ⎣<br />

0 −3 −2<br />

1 −1 1<br />

−1 3 1<br />

A w1 0<br />

A p1(A) = A2 + 2A + I.<br />

w2 p2(A) = A2 − A − 2I, w3 p3(A) = A3 − 3A − 2I<br />

0 A <br />

p1(t) = (t + 1) 2 , p2(t) = (t + 1)(t − 2) p3(t) = (t + 1) 2 (t − 2) <br />

mA(t) = (t + 1) 2 (t − 2).<br />

W = ker (A + I) 2 ⊕ ker(A − 2I). A + I <br />

W1 = ker (A + I) 2 2 <br />

(A + I) · x = 0 1 <br />

<br />

s1 =<br />

⎡<br />

⎣ −1<br />

−1<br />

1<br />

v A + I s1<br />

(A + I) · x = s1 <br />

<br />

xW =<br />

⎡<br />

⎣ ξ1<br />

ξ2<br />

ξ3<br />

⎤<br />

⎦ =<br />

⎡<br />

⎣ −1<br />

0<br />

0<br />

⎤<br />

⎦ +<br />

⎤<br />

⎦ ,<br />

⎡<br />

⎣ −1<br />

−1<br />

1<br />

⎤<br />

⎦<br />

⎤<br />

⎦ · τ, τ ∈ C.<br />

v = −w1. {s1 = (A + I)(v), v} <br />

W1 = ker (A + I) 2 <br />

(A − 2I) · x = 0 <br />

<br />

ker(A − 2I) = {x | x = τ(−w1 + w3), τ ∈ C}<br />

1 −w1 + w3 2 <br />

J = {(A + I)(v), v, −w1 + w3} W<br />

<br />

(A(A + I))(v) = (A + I) 2 (v) − (I(A + I))(v) = −(A + I)(v),<br />

A(v) = (A + I)(v) − v,


A(−w1 + w3) = 2(−w1 + w3),<br />

A J <br />

⎡<br />

−1<br />

AJ = ⎣ 0<br />

1<br />

−1<br />

0<br />

0<br />

⎤<br />

⎦ .<br />

0 0 2<br />

(A + I)(v) = s1 = −w1 − w2 + w3 v = −w1, W J<br />

B <br />

⎡<br />

BW = ⎣<br />

−1 −1 −1<br />

−1 0 0<br />

1 0 1<br />

AW BW <br />

<br />

AJ = B −1<br />

W AWBW.<br />

<br />

A<br />

<br />

i(= 1, . . . , r) mi0 = 1 A <br />

(t − λi)<br />

ker(A − λiI) 1<br />

(vi0, A − λiI) = (vi0), . . . ,(vis, A − λiI) = (vis)<br />

A <br />

<br />

<br />

<br />

V F A ∈ L(V ) A <br />

A <br />

F[t] <br />

<br />

<br />

<br />

<br />

<br />

⎤<br />

⎦ ,


n <br />

n


n <br />

n


k


k

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