Wu Chong-shi
a0a1a2a1a3 a4 a5 a6 (
a7)
a8Helmholtz
a9a10a11a12a13a14a15a16a17a18a19a20a21a22a23a24a25a26a27a28a17a9a10
1
r
d
dr
bracketleftbigg
rdR(r)dr
bracketrightbigg
+
bracketleftBig
k2 ?λ? μr2
bracketrightBig
R(r) = 0.
a29a30k2 ?λ negationslash= 0
a22a31a19a32x = √k2 ?λr, y(x) = R(r)a22a33a9a10a19a34 (ν a35)Bessela9a10
1
x
d
dx
bracketleftbigg
xdy(x)dx
bracketrightbigg
+
bracketleftbigg
1? ν
2
x2
bracketrightbigg
y(x) = 0,
a36a37μ = ν2
a38
a39a40a41a392
a42
a37a43
a24a44a45a46Bessela9a10a11x = 0a47a48a49a33a50
a38
a16a51a52a53a54a55a56a57a16
a43
a24a25a26a48a58
a30
a38
§22.1 Bessel a59a60a61 Neumann a59a60
Bessela62a63a64a65a66a67a68a69 x = 0a70x = ∞a71x = 0a72a73a74a67a68a22 x = ∞a72a75a73a74a67a68
a38
a76
a73a74a67a68 x = 0a77a22a78a79ρ = ±ν a38
a80ν negationslash=
a81a82a83a22 Bessela62a63a84a65a66 (a85a86a87a88) a73a74a89a72
J±ν(x) =
∞summationdisplay
k=0
(?)k
k!Γ(k ±ν + 1)
parenleftBigx
2
parenrightBig2k±ν
.
a90a91ν =
a81a82na22a74Jn(x)a70J?n(x)a85a86a92a88a22
J?n(x) = (?)nJn(x),
a93
a83a22 Bessela62a63a84a94a95a89a96a72 Jn(x)a22a94a97a89a74a98a99a100
Nn(x) = limν→n cosνpiJν(x)?J?ν(x)sinνpi
= 2piJn(x)ln x2 ? 1pi
n?1summationdisplay
k=0
(n?k?1)!
k!
parenleftBigx
2
parenrightBig2k?n
?1pi
∞summationdisplay
k=0
(?)k
k!(k + n)!
bracketleftbigψ(n + k + 1)+ψ(k + 1)bracketrightbigparenleftBigx
2
parenrightBig2k+n
,
a101a102a103a104
a22
a80 n = 0
a83a22a105a106a107a108a109a110a111a94a97a112a84a64a113a70
a38
Wu Chong-shi
§22.1 Bessela114a115a116Neumanna114a115 a1172a118
a11922.1
a111a120a121a122a123
a124a125
a100a126a82a83a127a128a66 Jn(x)a84
a119a129
a38
a13022.1 Bessel
a131a132
a127a128a66 Nn(x)a84
a119a129a133a119 22.2
a38
a13022.2 Neumann
a131a132
a134
a82a108a109a110a72 Bessela135a82a84a136a137a108a109a110a22a138a139a98a140a141a121 Bessela135a82a84a95a142a143a144a86a145a22a146
a90a147
a141a88a148 (a133a149a95a150)a38a151a152 Bessela135a82a84
a134
a82a108a109a110a22a153a98a140a154a155a156a142a157a158a84a159a160a22a146
a90a161a162a163a164
a165a166a164a163a164a167 Bessela163a164a168a169a162a168a162a170
a38
Wu Chong-shi
a171a172a173a172a174 a175
a114 a115 (a176) a1173a118
a177 22.1
a154a155a159a160
integraldisplay ∞
0
e?axJ0(bx)dx, Rea > 0.
a178 a179a180Bessel
a135a82a84
a134
a82a108a181a22
a101a182
a112a159a160
a38
integraldisplay ∞
0
e?axJ0(bx)dx =
integraldisplay ∞
0
e?ax
∞summationdisplay
k=0
(?)k
(k!)2
parenleftbiggbx
2
parenrightbigg2k
dx
=
∞summationdisplay
k=0
(?)k
(k!)2
parenleftbiggb
2
parenrightbigg2k integraldisplay ∞
0
e?axx2kdx =
∞summationdisplay
k=0
(?)k
(k!)2
parenleftbiggb
2
parenrightbigg2k (2k)!
a2k+1
= 1a
∞summationdisplay
k=0
1
k!
parenleftbigg
?12
parenrightbiggparenleftbigg
?32
parenrightbiggparenleftbigg
?52
parenrightbigg
···
parenleftbigg
?2k?12
parenrightbiggparenleftbiggb
a
parenrightbigg2k
= 1a
bracketleftBigg
1 +
parenleftbiggb
a
parenrightbigg2bracketrightBigg?1/2
= 1√a2 + b2.
a93a183a184a185
a84a186a68a72
a134
a82a187a70a22a187a70a83a153a188a188a189a64a95
a104
a84a113a190a191a192
a38
a146
a90a76a193a194
a187a70a83a195a189a187|b/a| <
1a38a196a195a137a197a198a199a22
a200a201a202a203
a22
a204a205
a84a159a160
a76 Rea > 0
a84a206a207a208a209a210a111a95a211a212a213a22
a214
a198
a76 Rea > 0
a84a206a207a209a210a215a89a216a71a198a159a160a121a84a217
a91a218a76a219
a95a209a210a215a89a216
a38a220a221
a89a216a222a223a84
a204a224
a22a195a98a140a106a107
a93
a66a113a190a191a192
a38
Wu Chong-shi
§22.2 Bessela114a115a225a226a227a228a229 a1174a118
§22.2 Bessel a59a60a230a231a232a233a234
Bessela135a82 J±ν(x)a84a136a137
a147
a141a88a148a72
d
dx [x
νJν(x)] = xνJν?1(x),
d
dx
bracketleftbigx?νJ
ν(x)
bracketrightbig = ?x?νJ
ν+1(x).
a235 a236a202a203
d
dx [x
νJν(x)] = xνJν?1(x).
a100a139a22a237a238a239 Bessela135a82a84
a134
a82a108a109a110
Jν(x) =
∞summationdisplay
k=0
(?)k
k!Γ(k + ν + 1)
parenleftBigx
2
parenrightBig2k+ν
a121a240
a38
a138a241
a134
a82
a76a242a243a194
a212a213a22a244a140a98a140
a182
a112a245a246
a38
d
dx [x
νJν(x)] = d
dx
∞summationdisplay
k=0
(?)k
k!Γ(k + ν + 1)
x2k+2ν
22k+ν
=
∞summationdisplay
k=0
(?)k
k!Γ(k + ν)
x2k+2ν?1
22k+ν?1 = x
νJν?1(x).
a219a247
a22
d
dx
bracketleftbigx?νJ
ν(x)
bracketrightbig = d
dx
∞summationdisplay
k=0
(?)k
k!Γ(k + ν + 1)
x2k
22k+ν
=
∞summationdisplay
k=0
(?)k+1
k!Γ(k + ν + 2)
x2k+1
22k+ν+1 = ?x
?νJν+1(x). (square)
a76a93
a65a66
a147
a141a88a148a111a248a106 Jν(x)a249Jprimeν(x)a22a250a98a140a251a252a65a66a253a84
a147
a141a88a148a69
Jν?1(x)?Jν+1(x) = 2Jprimeν(x),
Jν?1(x) + Jν+1(x) = 2νx Jν(x).
a239
a93
a142
a147
a141a88a148a98a140a254a121a22a206a207a81a82a255a84 Bessela135a82a22a0a98a140
a152 J0(x)
a70 J1(x)a108a181a121
a205
a38
a1a2
a72a22
a76
d
dx
bracketleftbigx?νJ
ν(x)
bracketrightbig = ?x?νJ
ν+1(x)
a111a3ν = 0a22a153a4a251a252
Jprime0(x) = ?J1(x).
a220a221Nν(x)
a84
a104a5
Nν(x) = cosνpiJν(x)?J?ν(x)sinνpi
a6J
ν(x)a84
a147
a141a88a148a22a98a140a7a121 Nν(x)a84
a147
a141a88a148a22a143
a129
a110a70 Jν(x)a8
a242
a92
a219
a38
d
dx [x
νNν(x)] = xνNν?1(x),
Wu Chong-shi
a171a172a173a172a174 a175
a114 a115 (a176) a1175a118
d
dx
bracketleftbigx?νN
ν(x)
bracketrightbig = ?x?νN
ν+1(x).
a9a10a147
a141a88a148
d
dx [x
νCν(x)] = xνCν?1(x),
d
dx
bracketleftbigx?νC
ν(x)
bracketrightbig = ?x?νC
ν+1(x)
a84a135a82{Cν(x)}a11a12a100a13a135a82
a38
a98a140
a202a203
a69a13a135a82a95
a104
a72 Bessela62a63a84a89
a38
Bessela135a82a72a94a95a157a13a135a82a22 Neumanna135a82a72a94a97a157a13a135a82
a38
Bessela135a82
a147
a141a88a148a84
a151a152a14
a95a22a72a154a155a15Bessela135a82a84a159a160
a38a16
a189
a152
a241
a161a162a163a164a165a17a163a164
a167Bessela163a164a168a169a162
a84a18
a129
a38
a177 22.2
a154a155a159a160
integraldisplay 1
0
parenleftbig1?x2parenrightbigJ
0(μx)xdxa22a143a111J0(μ)=0a38
a178 a19
a152
a147
a141a88a148
d
dx [x
νJν(x)] = xνJν?1(x).
a160a20a159a160a22a64 integraldisplay
1
0
parenleftbig1?x2parenrightbigJ
0(μx)xdx =
integraldisplay 1
0
parenleftbig1?x2parenrightbig 1
μ
d
dx [xJ1(μx)]dx
= parenleftbig1?x2parenrightbig 1μ [xJ1(μx)]
vextendsinglevextendsingle
vextendsingle
1
0
+ 2μ
integraldisplay 1
0
x2J1(μx)dx
= 2μ2x2J2(μx)
vextendsinglevextendsingle
vextendsingle
1
0
= 2μ2J2(μ).
a21
a3
a147
a141a88a148
Jν?1(x) + Jν+1(x) = 2νx Jν(x)
a111ν = 1a22
J0(x) + J2(x) = 2xJ1(x),
a101a22a23
a252 J0(μ) = 0a22a195a64
J2(μ) = 2μJ1(μ).
a179a180a24
a251 integraldisplay
1
0
parenleftbig1?x2parenrightbigJ
0(μx)xdx =
4
μ3J1(μ).
Wu Chong-shi
§22.3 Bessela114a115a225a25a26a27a28 a1176a118
§22.3 Bessel a59a60a230a29a30a31a32
Bessela135a82a84a33a34a35a36a64a65
a183
a136a137a157a158
a38
a95
a183a37
a152
a241 x→0a22
Jν(x) = 1Γ(ν + 1)
parenleftBigx
2
parenrightBigν
+ Oparenleftbigxν+2parenrightbig.
a93
a98a140a237a238a138Bessela135a82a84
a134
a82a108a109a110a251a252
a38a38
a95
a183
a33a34a35a36
a37
a152
a241 x → ∞a22
Jν(x) ~
radicalbigg 2
pix cos
parenleftBig
x? νpi2 ? pi4
parenrightBig
, |argx| < pi.
a93
a66a39a110a84a141a7a40a41a189
a152
a252a206a207a255Bessela135a82a84a159a160a108a181a22a153a189
a152
a252a95
a183a1a42
a84a43a44(a45a68
a185
a22a249
a12a46a47
a149a48a185)
a38
a49a50
a84a141a7a98
a133a51a22a52a53[3]
a84a947a54
a38
a76a51a22a52a53[1]
a111
a218
a120a121a122a81a82a255Bessel
a135a82a33a34a35a36a84
a202a203
a38
a80x → 0, Reν > 0
a83a22Nν(x)a84a33a34a55a100a138 J?ν(x)a56
a104
a22
Nν(x) ~?Γ(ν)pi
parenleftBigx
2
parenrightBig?ν
.
a198a57a241 N0(x)a22a98a138
Nn(x) = 2piJn(x)ln x2 ? 1pi
n?1summationdisplay
k=0
(n?k?1)!
k!
parenleftBigx
2
parenrightBig2k?n
? 1pi
∞summationdisplay
k=0
(?)k
k!(k + n)!
bracketleftbigψ(n + k + 1)+ψ(k + 1)bracketrightbigparenleftBigx
2
parenrightBig2k+n
,
a237a238a251a252
N0(x) ~ 2pi ln x2.
a244a140a22a58a59ν a72a60a100a81a82a22 Nν(x)a76x = 0a68a61a72a240a62a84
a38
a153a98a140
a202a203
a22
a80 x → ∞
a83a22Neumanna135a82a84a33a34a108a109a110a72
Nν(x) ~
radicalbigg 2
pix sin
parenleftBig
x? νpi2 ? pi4
parenrightBig
, |argx| < pi.
Wu Chong-shi
a171a172a173a172a174 a175
a114 a115 (a176) a1177a118
§22.4 a63a60a64 Bessel a59a60a230a65a66a59a60a61a67a68a69a70
Bessela62a63
1
x
d
dx
bracketleftbigg
xdy(x)dx
bracketrightbigg
+
bracketleftbigg
1? ν
2
x2
bracketrightbigg
y(x) = 0
a111a84ν2 ≡ μa22a40a41a72a138a137a71a72a73a197
Φprimeprime + μΦ = 0,
Φ(0) = Φ(2pi), Φprime(0) = Φprime(2pi)
a56
a104
a84a22μ = m2, m = 0,1,2,···a38a214a139a22a137a150
a1a2a74a75
a81a82a255 Bessela135a82
a1
a64a84a86a145
a38
1. Jn(x) a168a76a77a163a164a78a79a80(a133a94 7a81a146 7.4)
exp
bracketleftbiggx
2
parenleftbigg
t? 1t
parenrightbiggbracketrightbigg
=
∞summationdisplay
n=?∞
Jn(x)tn, 0 < |t| < ∞.
2. Jn(x) a168a162a170a82a83
Jn(x) = 1pi
integraldisplay pi
0
cos(xsinθ ?nθ)dθ.
a235 a76Bessel
a135a82a84a84a85a135a82a35a36a110a111a3t = eiθ a22a195a251a252
eixsinθ =
∞summationdisplay
n=?∞
Jn(x)einθ.
a93
a195a72a135a82 eixsinθ a84a86a87a88a35a36a110 (a89a82
a129
a110) a38a241a72a22a138a86a87a88a35a36a84a148a82a39a110a22a195a4
a202
a251
Jn(x), = 12pi
integraldisplay pi
?pi
eixsinθ parenleftbigeinθparenrightbig? dθ
= 12pi
integraldisplay pi
?pi
[cos(xsinθ ?nθ) + isin(xsinθ ?nθ)]dθ.
a76a90a91
a159a160a84a92a159a135a82a111a22a93a20a72a67a135a82a22a159a160a100 0a22a244a140a195
a202
a251 Jn(x)a84a159a160a108a181
a38 square
Jn(x)a84a159a160a108a181a22
a218
a98a140
a152
a205
a154a155a15 Bessela135a82a84a159a160
a38
a146
a90
a57a241a146 22.1 a111a84a159a160a22a64integraldisplay
∞
0
e?axJ0(bx)dx =
integraldisplay ∞
0
e?ax
bracketleftbigg 1
2pi
integraldisplay pi
?pi
eibxsinθdθ
bracketrightbigg
dx
= 12pi
integraldisplay pi
?pi
dθ
integraldisplay ∞
0
e?(a?ibsinθ)xdx = 12pi
integraldisplay pi
?pi
dθ
a?ibsinθ.
a152a94
a82
a104a224
a154a155
a93
a66a159a160a22integraldisplay
∞
0
e?axJ0(bx)dx = 12pii
contintegraldisplay
|z|=1
2dz
?bz2 + 2az + b
= 1?bz + a
vextendsinglevextendsingle
vextendsingle
z=(a?√a2+b2)/b
= 1√a2 + b2.
a195a137a197a198a199a22
a93a183a184a185
a189a95
a179a180 Bessel
a135a82a84
a134
a82a108a109a110a96
a200a201
a142a22
a214
a100a97
a76
a84a154a155a98a99
a203a100
a22
a58a101
a134
a82a187a70a96a102a64a43a44a86
a38
a93a183a184a185
a84
a38
a95a66a103a77a72a58a105a104a89a216a222a223
a38
Wu Chong-shi
§22.4 a105a115a106Bessela114a115a225a107a108a114a115a116a109a110a111a112 a1178a118
a90a91a76 Bessel
a135a82a84a84a85a135a82a35a36a110
exp
bracketleftbiggx
2
parenleftbigg
t? 1t
parenrightbiggbracketrightbigg
=
∞summationdisplay
n=?∞
Jn(x)tn, 0 < |t| < ∞.
a111a3t = ieiθ a22a153a98a140a251a252
eixcosθ =
∞summationdisplay
n=?∞
Jn(x)ineinθ = J0(x) + 2
∞summationdisplay
n=1
inJn(x)cosnθ.
a1a2
a72a22
a90a91a21
a3x = kra22a241a72a195a64
eikrcosθ = J0(kr) + 2
∞summationdisplay
n=1
inJn(kr)cosnθ.
a113a193
a110a111a84 r a70θ a224a89a100a13a114a79a148a111a84a114a79
a124a125
a22
a101a102a113 k a224
a89a100a115a82a22
a219
a83a99a92a116a84a83a117
a214a118
a100 e
?iωt
a22a74
a193
a110a65
a91
a61a160
a2
a57
a151
a241a115a119a120a63a92a116
a214a118
a84a121a117a20a160a69a122
a91
a72a123a73 xa124a62a125a126a127a128
a84
a243a194
a115a22
a214
a100a129a84a130a92a116
a194
a72
krcosθ ?ωt =a41a82;
a198
a90a91a131
a112a111a84 J0(kr)a70Jn(kr)a132a133a84a72a13
a194
a115
a38
a214
a139a22
a93
a66a35a36a110a84a207
a5
a195a72
a243a194
a115a134a13
a194
a115
a35a36
a38
a97
a76a205
a89a135a100a136a137Jν(kr)a132a133a84a72a13
a194
a115
a38
a138Bessela135a82a84a33a34a35a36
Jν(x) ~
radicalbigg 2
pix cos
parenleftBig
x? νpi2 ? pi4
parenrightBig
, |argx| < pi. (maltesecross)
a98a140a254a121a22
a80 ra10a138a139
a83a22 Jν(kr)a244a132a133a84a115a119a120a63a84a92a116a195a72
cos
parenleftBig
kr?νpi2 ?pi4
parenrightBig
e?iωt = 12
braceleftbigg
exp
bracketleftBig
i
parenleftBig
kr?νpi2 ?pi4?ωt
parenrightBigbracketrightBig
+exp
bracketleftBig
?i
parenleftBig
kr?νpi2 ?pi4 +ωt
parenrightBigbracketrightBigbracerightbigg
,
a130a92a116
a194
a72a13
a194
kr? νpi2 ? pi4 ?ωt =a41a82,
a160
a2
a132a133a84a72a130a92a116
a194a140a141
a83a117a58a142a143
a139
a249a212a144a84a240a62a249a145a146a84a13
a194
a115
a38
a198
a102
a22a138a241 (maltesecross)a110a111a153
a15a64a147
√r
a85a148a95a84a149a150
a214a118
a22a115a119a120a63a84a4a151a152a153a195a147ra85a148a95a22a98a72a138a241a154a13a84a155
a194
a159a147ra85
a73a95a22a244a140a156a116a83a117a215a40a120a157a66a154a13
a194
a151a120a84a0a4
a125
a58
a124
a38
a93
a195a72a158a22 (maltesecross)a110a132a133a84a153a72a95a66a58
a159a160
a84a13
a194
a115
a38
a219a247
a22 Nν(x)
a218
a98a140
a152
a205
a132a161a13
a194
a115a22
a218
a72a240a62a84a13
a194
a115a70a145a146a84a13
a194
a115a84a162a163
a38
a128a164a165a166a167a168a169a170a171a172a173a174a175a171a176a177a178a179a180a181a182a183a172a173a174a175a184
eiωta185a186a187a188a189a190a191a192
a167a193
xa194
a166a167a164a165a171a180