On The Covariant Tangent Vector Coordinate Systems
Haewon Lee ∗
Department of Physics, Chungbuk National University, Cheongju 361-763, Korea (Received 19 December 2014 : revised 9 January 2015 : accepted 12 January 2015)
A method that can be used to express covariant derivatives and metric tensors by using tangent vectors in a curved space-time is introduced. In addition to this, parallel transport along geodesics is incorporated. As a result, the new differential operators can be expanded as polynomials of the tangent vectors and the covariant local functions at a given point. This result can be used to find the metric tensor in the tangent-vector’s coordinate system. This metric tensor can also be expanded by using tangent vectors and Riemann curvature tensors. The covariant derivatives and the metric tensor are calculated up to local functions of dimension 6.
PACS numbers: 03.70.+k, 04.62.+v, 11.10.-z
Keywords: Tangent vector, Covariant derivative, Curved space-time
« ì Å ± n É Ò Ås ð ' [ Ò ÷ »4 ; c 6 X ¢ ì Å
T
A I4 w H ∗
Ø
æ· ¡ ¤ @ / < Æ § Ó ü t o < Æõ , ' õ AÅ Ò 361-763
(2014¸ 12 Z 4 19{ 9 ~ Ã Î6 £ §, 2015¸ 1 Z 4 9{ 9 Ã º& ñ : r ~ Ã Î6 £ §, 2015¸ 1 Z 4 12{ 9 > F S X & ñ )
Ï ã
L # Q r / B N ç ß \ " f / B N p ì r í ß ü < B jà Ôa Ë :J $ " f\ ¦ ] X 7 ' (tangent vector) ý a³ ð> \ ¦ 6 x #
³
ð & ³ H ~ ½ ÓZ O ` ¦ ½ ¨ % i . # l \ t 2 £ §U ´(geodesic)` ¦ ¨ î ' s 1 l x` ¦ H כ ` ¦ Æ Òô Ç . s X O
>
í ß [ þ t É r l ï r & h \ " f_ / B N © [ þ t õ ] X 7 ' [ þ t Ð ³ ð & ³ ) a ½ Ód Ü ¼ Ð > h 0 p x .
/
B N p ì r í ß \ @ /K s _ õ \ ¦ S X © # | 9 | ¾ Ó " é ¶ s 6 / B N © [ þ t` ¦ í < Êô Ç ½ Ó[ þ t t ½ ¨
%
i . s õ H ] X ý a³ ð> \ " f B jà Ôa Ë : J $ " f\ ¦ ½ ¨ H X <\ ¸ 6 x| ¨ c à º e . s B jà Ôa Ë : J $ " f H ] X
7 ' ü < o ë ß / B GÒ ¦J $ " f_ ½ Ód Ü ¼ Ð > h ) a . B jà Ôa Ë : J $ " f\ @ /K " f ¸ 6 ½ Ó t _ õ \ ¦ ] jr
% i .
PACS numbers: 03.70.+k, 04.62.+v, 11.10.-z Keywords: ] X 7 ' , / B N p ì r, Ï ã L É r r / B N ç ß
∗
E-mail: [email protected]
170
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License
(http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any
medium, provided the original work is properly cited.
I. " e  ] Ø
þ
j H \ $ H Ï ã L # Q r / B N ç ß \ " f ª © : r \ 1 p x ©
H p ì r í ß [ þ t` ¦ r / B N ç ß ý a³ ð x @ / \ ] X 7 ' ý a
³
ð X \ ¦ 6 x # ³ ð & ³ H ~ ½ ÓZ O ` ¦ è> h % i [1–3]. 1 s
Qô Ç p ì r í ß [ þ t É r > s t ¨ 8 õ ý a³ ð ¨ 8 \ @ /K /
B N & h (covariant) s . # l \ t 2 £ §U ´ (geodesic)` ¦
¨ î ' s 1 l x` ¦ H כ ` ¦ í < Êr & D h Ðî r p ì r í ß
\
¦ & ñ _ H X < s X O > 8 a % ~ É r / B N & h : £ ¤$ í ` ¦ t
> ÷ &# Q # Q / B M \ 6 £ x6 x ½ + É Ã º e . Heat Kernelõ ° ú
É
r í ß _ & V , (kernel)` ¦ D h Ðî r p ì r í ß \ ¦ 6 x
7 á § 8 ¼ # o > è q à º e . 2 ¢ ¸ô Ç ª © : r \
"
f ´ òõ 6 x | ¾ Ó (effective action)` ¦ / B N p ì r © [ þ t Ð > h (derivative expansions) H X < ¼ # o > 6 x ) a [4].
s
~ ½ ÓZ O \ " f H r / B N ç ß _ ô Ç & h x \ ¦ & ñ ¦ s & h \
"
f_ ] X 7 ' (X)\ ¦ r / B N ç ß ` ¦ l Õ ü t H D h Ðî r ý a³ ð Ð
6 x H כ s . & h x ü < X @ /³ ð H É r & h ˜ x ç ß _
& V , É r x ü < X _ < ÊÃ º Ð ³ ð & ³÷ & H X < X Å Ò ` ¦ M
:_ s & V , _ ' 1 l x (behavior) É r < É ª p _ @ / © s . $
H ] X 7 ' ý a³ ð> \ ¨ î ' s 1 l x` ¦ í < Êr v H ~ ½ ÓZ O ` ¦
¸{ 9 # { 9 ì ø Í& h 4> í ß \ @ /K heat kernel > h
½ Ó[ þ t` ¦ > í ß % i % 3 [1,3].
s
~ ½ ÓZ O \ " f p ì r í ß [ þ t É r r / B N ç ß ý a³ ð x \ " f / B N
& h < Êà ºü < ] X 7 ' [ þ t ¢ ¸ H ] X 7 ' \ @ /ô Ç p ì r
í ß \ ¦ Y L ô Ç + þ AI _ ½ Ó[ þ t _ ½ + ËÜ ¼ Ð ³ ð & ³ ) a . s ] j p ì
r í ß [ þ t É r ] X 7 ' ý a³ ð\ @ /ô Ç p ì r í ß Ð ^ ¦ Ã
º e ¦ x H à º\ ¦ ° ú H / B N & h < Êà º[ þ t É r © à ºü < ° ú s
2 [/ å L ) a . í ß \ ¦ s X O > ³ ð & ³ & V , ` ¦ ½ ¨ H X
< / B N $ í s ½ Ó © Ä »t ÷ & ¦ > í ß s é ß í H # t > ) a .
: r ½ ¨\ " f H õ \ ¦ S X © # p ì r í ß \ ¦ | 9
|
¾ Ó " é ¶ s 6 / B N < ÊÃ º\ ¦ í < Ê H ½ Ó t ½ ¨ % i .
¢
¸ô Ç s > í ß _ Â Òí ß Ó ü t Ð B jà Ôa Ë : J $ " f\ ¦ ] X 7 ' ý a³ ð
>
\ " f O(X 6 ) t ½ ¨ % i .
II. « ì Å ± n É Ò Ås ð ' [ Ò ÷ »4
$ / B N ] X 7 ' ý a³ ð> \ @ /K ç ß é ß y 4 ¤_ þ v` ¦ #
Ðl Ð . / B N p ì r í ß ∇ µ H ∇ µ = ∂ ν − iA µ + Γ µ õ
° ú s j þ t à º e . # l " f A µ ≡ A a µ T a H Yang-Mills
© ` ¦ Ø Ôv ¦ Γ µ H r / B N ç ß J $ " f Û ¼x -\ 6 x H o
ë ß s 6 £ § (connection) s . $ r / B N ç ß _ l ï r& h x
1
] X 7 ' ý a³ ð> H normal coordinate system s ¦ ¸ ô Ç .
2
í ß M\ @ /K & V , É r hy| M |xi \ ¦ _ p ô Ç .
\
¦ × þ ô Ç . r / B N ç ß _ É r & h ˜ x H & h x \ " f_ ] X 7 ' X µ ÐÂ Ò' & ñ | ¨ c כ s . 7 £ ¤ & h x \ " f ] X 7 ' X µ ~ ½ Ó ¾ ÓÜ ¼ Ð U ´s pX µ X ν g µν (x) t 2 £ §U ´` ¦ Õ ªo ì
ø Í@ /¼ # = å Q& h s ˜ x ) a . s Qô Ç ý a³ ð> \ ¦ ³ ðï r o ³ ð (normal coordinate system) ¦ ¸ Â Ò É r . ˜ x õ X µ ü <_
'
a > H s Û ¼º ú σ(˜ x, x) Ð ¸ ú è qà º e . [5,6] s
Û ¼º ú σ(˜ x, x) H x \ " f ˜ x t _ þ jé ß o (geodesic distance) _ ] jY L _ ì ø ÍÜ ¼ Ð & ñ _ ÷ & ¦ ˜ x õ X µ ü <_ ' a
>
H 6 £ § d Ü ¼ Ð Å Ò# Q .
X µ = −∇ µ σ(˜ x, x) = − ∂
∂x µ σ(˜ x, x). (1) σ(˜ x, x) H Hamilton-Jacobi ~ ½ Ó& ñ d
X µ X µ = 2σ (2)
\
¦ ë ß 7 á ¤ r . ¢ ¸ô Ç lim x→x ˜ ∇ ˜ µ ∇ ν σ(˜ x, x) = −g µν (x) s
. · ú ¡Ü ¼ Ð H Å Ò Ð / B N p ì r l ñ ∇ @ / \ & h (.) ` ¦ 6
x ½ + É כ s . ¢ ¸ô Ç oÛ ¼ 0 A\ ∼ e Ü ¼ ˜ x \ " f_ p ì
r s J $ " f oÛ ¼\ ¦ _ p ô Ç . 7 £ ¤ σ. µν ˜ ˜ λ = ˜ ∇ λ ∇ ν ∇ ˜ µ σ ü
< ° ú .
] X
7 ' ý a³ ð> \ " f H & h _ ý a³ ð ˜ x @ / \ X µ \ ¦ 6
x ô Ç . p ì r í ß M ¸ ] X 7 ' X µ \ ¦ 6 x # r
æ ¼# 4 R ô Ç . s \ $ l ï r& h x \ " f & h ˜ x t _
t 2 £ §U ´` ¦ " f ¨ î ' s 1 l x (parallel transportation)` ¦
# Ð . s M :_ ¨ î ' s 1 l x ' § > = (matrix) I(˜ x, x) H 6
£
§ _ d ` ¦ ë ß 7 á ¤ ô Ç .
X ˜ µ ∇ ˜ µ I(˜ x, x) = 0 = X µ I(˜ x, x) ← −
∇ µ I(x, x) = 1,
I(˜ x, x 0 )I(x 0 , x) = I(˜ x, x). (3)
#
l " f ˜ X µ = ˜ ∇ µ σ(˜ x, x) = ∂ ˜ ∂ x
µσ(˜ x, x) s ¦ I(˜ x, x) ← −
∇ µ =
∂
∂x
µI(˜ x, x) − I(˜ x, x)(−iA µ + Γ µ ) \ ¦ _ p ô Ç . ¢ ¸ô Ç 0 A\
"
f [ j & h x, x 0 Õ ªo ¦ ˜ x H ° ú É r t 2 £ §U ´ © \ e # Q ô Ç
.
{ 9
ì ø Í& h Ü ¼ Ð ª © : r \ ¸ H p ì r í ß M É r / B N
p ì r í ß ∇ µ ü < C â © (background field) φ Ð
? /t H X < s \ ¦ M ( ˜ ∇, φ(˜ x)) ü < ° ú s j þ t à º e ` ¦ כ s .
#
l \ ¨ î ' s 1 l x ' § > =` ¦ 6 x # D h Ðî r í ß M\ ¦
6 £ § õ ° ú s & ñ _ .
M ≡ I(x, ˜ x)M ( ˜ ∇, φ(˜ x))I(˜ x, x) = M (∇, φ). (4)
#
l " f ∇ = I(x, ˜ x) ˜ ∇ I(˜ x, x) s ¦ φ =
I(x, ˜ x) φ(˜ x) I(˜ x, x) s . 7 á § 8 ½ ¨^ & h ³ ð & ³ É r / B I
Ð# × ¦ כ s . s \ ¦ 0 AK " f H A _ d ` ¦ ë ß 7 á ¤ H
É
r s J $ " f(bi-tensor) g µν (˜ x, x) \ ¦ ¸{ 9 # ô Ç .
˜
x µ ∇ ˜ µ g αβ (˜ x, x) = 0 = X µ ∇ µ g αβ (˜ x, x), g µν (x, x) = g µν (x),
g µν (˜ x, x) = g νµ (x, ˜ x)
g µν (˜ x, x 0 )g ν λ (x 0 , x) = g µλ (˜ x, x). (5)
#
l " f ¸ [ j & h x, x 0 Õ ªo ¦ ˜ x H ° ú É r t 2 £ §U ´ © \ e
#
Q ô Ç . g µν (˜ x, x) \ " f ' Í P : oÛ ¼ µ H ' Í P : ý a
³
ð ˜ x \ 5 Å q ¦ ¿ º P : oÛ ¼ ν H ¿ º P : ý a³ ð x \ 5
Å
q ô Ç . " f / B N p ì r` ¦ ½ + É M :\ H o ë ß s 6 £ § É r K {
© ÷ & H oÛ ¼\ ë ß 6 x ô Ç . ª A á ¤ = å Q& h \ " f B jà Ôa Ë : J $
"
f\ ¦ Y L # oÛ ¼\ ¦ ` ¦ o ¦ ? /w n = Ã º e . \ V\ ¦ [ þ t g µ ν (˜ x, x) = g µλ (˜ x)g λν (˜ x, x) s . 0 A\ " f s p / å LÙ þ ¡1 p w s
_ p ì r" î t · ú § É r â Ä º y J $ " f oÛ ¼ 5 Å q ô Ç & h
`
¦ ì r" î y l 0 AK oÛ ¼0 A\ ∼ ` ¦ ³ ðl \ ¦ ½ + É כ s
. 7 £ ¤ g µν ˜ = g µν (˜ x, x) ü < ° ú .
g µν (˜ x, x) # Qb G> 6 x ÷ & H t · ú l 0 AK \ V\ ¦ [ þ t # Q p
ì r í ß B µ ˜ ∇ ˜ µ \ ¦ ¦ 9K Ð .
I(x, ˜ x) B µ ˜ ∇ ˜ µ
I(˜ x, x)
= I(x, ˜ x)B µ ˜ I(˜ x, x)I(x, ˜ x) ˜ ∇ µ I(˜ x, x)
= g µ ν (x, ˜ x)I(x, ˜ x)B ν ˜ I(˜ x, x)g µ λ (x, ˜ x)I(x, ˜ x) ˜ ∇ λ I(˜ x, x)
= B µ ∇ µ . (6)
#
l " f ∇ µ = g µ λ (x, ˜ x)I(x, ˜ x)( ˜ ∇ λ )I(˜ x, x) s ¦ B µ = g µ ν (x, ˜ x)I(x, ˜ x)B ν ˜ I(˜ x, x) s .
s
] j ý a³ ð ˜ x @ / \ ] X 7 ' X \ ¦ 6 x # í ß
C â © [ þ t` ¦ ¸¿ º x ü < X Ð ³ ð & ³ô Ç . $ ∇ µ H 6
£
§ õ ° ú s j þ t à º e .
∇ µ = g µ˜ ν
I(x, ˜ x)I(˜ x, x). ν ˜ − σ(˜ x, x). να ˜
∂
∂X α
(7) C
â © φ _ â Ä º H 0 A_ \ V\ " f s p ¶ ú ( R : r ü < ° ú .
C
â © φ J $ " f y J $ " f oÛ ¼\ @ /K g µν (x, ˜ x)
\
¦ Y L K ô Ç . \ V\ ¦ [ þ t
φ µ = g µ ν ˜ I(x, ˜ x)φ ν (˜ x)I(˜ x, x). (8)
· ú
¡Ü ¼ Ð H ] X 7 ' X Ð ³ ð & ³ ) a í ß M ` ¦ M x Ð
? /l Ð . M x _ & ñ _ ÐÂ Ò' M x & h x \ @ /K /
B N & h e ` ¦ ~ 1 > · ú Ã º e .
" f M x \ ¦ X µ ü < ∂X ∂
µ Ð > h\ ¦ 6 £ § õ ° ú
É
r g 1 J Ð j þ t à º e ` ¦ כ s .
M x = X
a α···βµ···ν (x)X α···β ∂
∂X µ · · · ∂
∂X ν , (9)
#
l " f X α···β ≡ X α · · · X β s ¦ a α···βµ···ν (x) H / B N & h
x _ J $ " f ' § > = < ÊÃ ºs . í ß _ Ã º (order) d s
X \ @ /ô Ç p ì r í ß _ Ã º ¸ d \ ¦ Å t · ú §
`
¦ כ s . Ä ºo H / B I 0 Aü < ° ú É r > h\ ¦ > í ß H ~ ½ ÓZ O
`
¦ è> h½ + É כ s . 0 A_ y ½ Ó\ " f / B N < ÊÃ º a α···βµ···ν
_
| 9 | ¾ Ó " é ¶` ¦ Dim(a) Ð ? / ¦, X\ @ /ô Ç Ã º\ ¦
#(X) Ð ∂X ∂
µ\ @ /ô Ç Ã º\ ¦ #(∂) Ð · p d = Dim(a) − #(X) + #(∂) ) a . ¢ ¸ô Ç s p / å L ô Ç@ / Ð
#(∂) ≤ d s .
III. ± n É Ò Å s ð ' [z º ¹ Å4 M
d
(9) ü < ° ú É r > h\ ¦ l 0 AK 6 £ § õ ° ú É r í ß
\
¦ & ñ _ ô Ç .
D ≡ X µ
∂
∂X µ
x
= X µ ∂ ˜ x ν
∂X µ
∂
∂ ˜ x ν
x
= ˜ X ν
∂
∂ ˜ x ν
x
= σ(˜ x, x). ν ˜
∂
∂ ˜ x ν
x
. (10)
#
l " f t } × ¦ _ d [ þ t É r ˜ X µ X ˜ µ = 2σ(˜ x, x) _ ª ` ¦ x ν Ð p ì r ¦ ' a > d ∂X
µ
∂ ˜ x
νx
= − ∂ ˜ X
ν
∂x
µ˜ x
`
¦ 6 x
#
7 £ x" î ½ + É Ã º e . X Ð > h ¦ z · É r < ÊÃ º e ` ¦ M :
#
l \ D \ ¦ 6 x r . X _ k ½ Ód \ 6 x r v
¦Ä »u k : r . \ V\ ¦ [ þ t X _ 1 ½ Ód ` ¦ è
9 D − 1 ` ¦ 6 x r v ¦ 1-2 ½ Ód ` ¦ è
9 (D − 1)(D − 2) \ ¦ 6 x r . s Qô Ç ~ ½ ÓZ O ` ¦ 6
x # d (7) î ß _ ½ Ó[ þ t` ¦ X Ð > hô Ç . s Qô Ç ~ ½ ÓZ O
`
¦ 6 x σ. µ ˜ ü < ° ú É r [ þ t s > 5 Å q ¸> ) a . ô Ç
¼
# X → 0 { 9 M : σ. µ ˜ → X µ ÷ &Ù ¼ Ð " é ¶ H Ã º ë ß
p
u _ σ. µ ˜ : r > í ß s ç ß é ß xt ë ß ½ Ó © Õ ªX O t
· ú
§ .
d
(7) \ Å Ò# Q í ß ∇ µ \ ¦ X Ð > h # Ðl Ð
. ' Í P : ½ Ó É r g µ ν ˜ I(x, ˜ x)I(˜ x, x). ˜ ν Ü ¼ Ð X _ 1 ½ ÓÂ Ò '
r ) a . 0 A\ " f / å L ô Ç ~ ½ ÓZ O @ / Ð D \ ¦ 6 x r & ¸ σ. µ ˜ ü < ° ú É r ¸t · ú § H X < @ / \ D + 1 ` ¦ 6 x r
v
(D + 1)g µ ν ˜ I(x, ˜ x)I(˜ x, x). ˜ ν = σ. λ ˜ g µ ˜ ν I(x, ˜ x)R λ˜ ˜ ν I(˜ x, x)
= −σ ∗˜ λ ν ˜ g µ ν ˜ I(x, ˜ x)I(˜ x, x). λ ˜
(11)
) a . # l " f R αβ ≡ [∇ α , ∇ β ] H / B GÒ ¦J $ " f í ß
Ð + '\ ¦ Ø Ô H J $ " f\ ¸ 6 x ô Ç . ¢ ¸ô Ç σ µ˜ ∗ ˜ ν ≡ σ. µ˜ ˜ ν − g µν (x) H O(X 2 ) s . " f g µ ν ˜ I(x, ˜ x)I(˜ x, x). ν ˜ =
1
2 X λ R λµ + O(X 2 ) e ` ¦ · ú Ã º e . ¢ ¸ô Ç D = σ. µ ˜ ∂ ˜ µ
\
¦ ˜ x \ " f Û ¼º ú ª < Êà º\ 6 x r ~ ´ M :\ H @ / \ D ≡ σ. µ ˜ ∇ ˜ µ \ ¦ 6 x r & ¸ ) a . · ú ¡Ü ¼ Ð ¸ H â Ä º H
¸¿ º s \ K { © ) a . ¢ ¸ô Ç Dσ. µ ˜ = σ. µ ˜ $ í | 9 s Å Ò 6
x ) a . D \ ¦ ì ø Í4 ¤& h Ü ¼ Ð 6 x r & | 9 | ¾ Ó " é ¶ s 6 s
/ B N < Êà º\ ¦ í < Ê H ½ Ó` ¦ ½ ¨½ + É Ã º e % 3 H X < õ \ ¦
&
ñ o 6 £ § õ ° ú .
g µ ν ˜ I(x, ˜ x)I(˜ x, x). ν ˜ = 1
2 R (1) µ + 1
3 R (2) µ + 1
8 R (3) µ − 1
16 σ (2)˜ λ µ ˜ R (1) λ
+ 1
30 R (4) µ − 13
600 σ (3)˜ λ µ ˜ R (1) λ − 1
30 σ (2)˜ λ µ ˜ R (2) λ
+ 1
144 R (5) µ − 7
864 σ (3)˜ λ µ ˜ R (2) λ − 1
96 σ (2)˜ λ µ ˜ R (3) λ
− 1
288 σ (4)˜ λ µ ˜ R (1) λ + 23 4800 σ (2) ˜ η ˜
λ σ (2)˜ λ µ ˜ R (1) η . (12)
#
l " f 6 £ § õ ° ú É r » ¡ ¤ ³ ð & ³` ¦ 6 x % i .
R (1) µ = X α R αµ , R (2) µ (X) = X αβ R αµ . β ,
R (3) µ (X) = X αβγ R αµ . βγ , · · · (13)
¢
¸ô Ç σ (2)˜ λ µ ˜ = X αβ σ. λ ˜
˜
µ ˜ α ˜ β | x=x ˜ , σ (3)˜ λ µ ˜ = X αβγ σ. ˜ λ µ ˜ ˜ α ˜ β ˜ γ | x=x ˜ s .
í ß ∇ µ _ ¿ º P : ½ Ó É r g µ˜ ν σ. να ˜ ∂X ∂
α