asymptotic flatness in higher dimensional spacetimesasymptotic flatness in higher dimensional...
TRANSCRIPT
Asymptotic flatness in higher
dimensional spacetimes
Tetsuya Shiromizu
Department of Physics, Kyoto University
KIPMU ACPseminar 20th June 2012
Based on
K.Tanabe, N. Tanahashi, T.Shiromizu, J.Math.Phys, 51, 062502(2010), ibid, 52, 032501(2011),
K.Tanabe, S.Kinoshita, T.Shiromizu, Phys. Rev. D84, 044055(2011), 1203.0452[PRD85(2012)]
K.Tanabe(Barcelona Univ. ), N.Tanahashi(UC Davis) S.Kinoshita(Osaka City Univ. )
Content
1. Introduction/black holes in 4D
2. Higher dimensional black holes
3. Asymptotics
4. Applications
5. Summay
1. Introduction/4D BH
Why higher dimensions?
String theory
Gauge/gravity correspondence
Black holes in LHC(?)
A famous cartoon? - “4D” pocket, Doraemon -
BHs in 4D
After gravitational collapse, black holes will
be formed.
Then spacetime will be stationary.
The black hole is described by the Kerr
solution.
The Golden age in 4D
The topology of stationary black holes is 2-
sphere. [Hawking 1972]
It is shown that stationary black holes are
axisymmetric(rigidity). [Hawking 1972]
Stationary and axisymmetric black hole is
unique. The Kerr solution! [Carter 1973,…]
The Schwarzschild solution is unique static
BH. [Israel 1967]
Then
The second Golden age?
A lot of remaining issues for
higher dimensional BHs.
It is a chance to have a “gold”.
Focus on higher dimensional GR
Vacuum Einstein equation
Asymptotically flat
Cosmic censorship conjecture
[no naked singularities]
3. Higher dimensional black holes
~ brief review ~
Recent reviews
Eds. K.-I. Maeda, T. Shiromizu, T. Tanaka
Higher dimensional black holes,
Progress of Theoretical Physics Supplement No. 189, 2011
Ed. G. Horowitz,
Black holes in higher dimensions,
Cambridge Univ. Press 2012
Schwarzschild in higher dimensions
・spherical symmetric
・topology: (D-2)-sphere
・any dimensions
Tangherlini 1963
Kerr in higher dimensions
Myers-Perry black holes
・rotating
・topology: (D-2)-sphere
・any dimensions
Myers&Perry 1986
Black rings Discovered by Emparan & Reall 2001
・D=5
・
・rotation is important
21 SS
Black object zoo
Black Saturn Elvang and Figueras, 2007
Di-Ring Iguchi and Mishima, 2007
Bi-Cycling Ring Izumi, 2008, Elvang and Rodriguez, 2008
and so on
Rigidity theorem
Hawking 1972 4D, stationary, rotating, asymptotically flat black holes are
axisymmetric
Hollands, Ishibashi & Wald 2006 any dimensions, stationary, rotating, asymptotically flat black
object spacetimes are axisymmetric.
Topology
Hawking 1972 The topology of 4D, stationary, rotating, asymptotically flat
black hole is 2-sphere
Galloway & Schoen 2005
In higher dimensions,
"0" )2(
S
D RdS
sum connected , , :5 213 SSSD
:Ricci scalar of BH cross section RD )2(
“Uniqueness” ≈ classification
Gibbons, Ida & Shiromizu 2002
Higher dimensional Schwarzschild spacetime is unique static
vacuum BH.
Morisawa & Ida 2004
In D=5, the Myers-Perry solution is unique stationary vacuum
BH if the topology is 3-sphere and 2 rotational symmetries are.
…, Hollands & Yazadjiev 2007
In D=5, stationary BH with 2-rotational symmetries can be
classified by mass, angular momentum and rod
structure(~topology)
Stability
Schwarzschild BH is stable[Ishibashi & Kodama 2003]
Ultraspinning Myers-Perry(MP) solution (D>5) was
conjecture to be unstable [Emparan & Myers 2003]
confirmed by a numerical study[Shibata & Yoshino 2009-2010]
settle down to BH with lower angular momentum.
Remaining issues
Stability
Although there are many efforts…
Complete classification
requirement of rod structure(≈topology,…) is too strong…
Construction of exact solution in D>5
need a new way to find (exact) solution…
blackfold approach…? Emparan et al 2009
Asymptotic structure
3. Asymptotics
Asymptoics
Naïve concept
)||/1( 3 D
ijij xOg
2
2
||
1D
xt
Og null infinity
t
x
spatial infinity
curries the information of dynamics
How to analyze
…, Ashtekar & Hansen 1978, Hollands & Ishibashi 2005
conformal completion method
finite0
g~2
0 infinity
Minkowski spacetime
spatial infinity
null infinity
0 2g~
embemded into the Einstein static universe
rturt, vuv ,)1()1(4Ω 1212
uvuv 1111 tantan ,tantan
)sin(~ 222222 dddddxdxg
)0 , ,(
Einstein static universe
Conformal treatment in general
rg /1~ ,g~ 2
Near null infinity , where hg )/1( 12/ DrOh
12/~ Dh
g~in coordinate a be toused is
-The half-integer for odd dimensions.
-It is supposed that the conformally transformed spacetime is regular.
-Without solving the Einstein equation, one discusses the asymptotics in the physical
spacetime.
-As a result, we encounter the bad behavior because of the half-integer for odd
dimensions.
Conformal treatment in general
The conformal treatment
does not work for odd
dimensions…
Introduce the Bondi coordinate and then solve
the Einstein equation near the null infinity.
Bondi coordinate
sphere-)2(unit of volume:
,)det(
2
2
D
h
D
DIJ
))((2 222 duCdxduCdxhrdudreduAeds JJII
IJ
BB
)(
)(),(),(1
)12/(
2/)2()12/(
D
IJIJ
DIDD
rOh
rOCrOBrOA
Vacuum Einstein equation
constr constu
infinity null :r
Definition of asymptotic flatness
2)det( DIJh
))((2 222 duCdxduCdxhrdudreduAeds JJII
IJ
BB
)(
)(),(),(1
)12/(
2/)2()12/(
D
IJIJ
DIDD
rOh
rOCrOBrOA
The spacetime is said to be asymptotically flat if the
metric in the Bondi coordinate behaves like
Bondi coordinate
Bondi mass ))((2 222 duCdxduCdxhrdudreduAeds JJII
IJ
BB
22/
0
2/5
312/
)1(
)/1(),(
1Dk
k
D
D
I
kD
kB
uu rOr
xum
r
AAeg
)1()1( k
IJ
JIk hDDA
2
16
2)(
DSBondi md
DuM
of because integral surface the tocontributenot does )1( kA
Bondi mass loss law ))((2 222 duCdxduCdxhrdudreduAeds JJII
IJ
BB
22/
0
2/5
312/
)1(
)/1(),(
1Dk
k
D
D
I
kD
kB
uu rOr
xum
r
AAeg
2
16
2)(
DSBondi md
DuM
derivative total)2(2
1 )1()1(
IJ
uIJuu hhD
m
032
1)(
2
)1()1(
dhhuM
du
dDS
IJ
uIJuBondi
The Einstein equation implies
Flux of gravitational waves
Bondi mass loss law
032
1)(
2
)1()1(
dhhuM
du
dDS
IJ
uIJuBondi
Flux of gravitational waves
constu
infinity null :r
spatial infinity
u
initialfinalBondi
ADMinitialBondi
MMM
MMM
)(
0)(
Gravitational wave curries the
positive energy
Asymptotic symmetry
))((2 222 duCdxduCdxhrdudreduAeds JJII
IJ
BB
g
0 ,0 ,0 IJ
IJ
rIrr gggg
)(
)(),(),(1
)12/(
2/)2()12/(
D
IJIJ
DIDD
rOh
rOCrOBrOA
Bondi coordinate condition
)(2
,),(
),,(
2
I
II
Ir
J
IJB
III
Iu
fDfDCD
r
fDhr
edrxuf
xuf
2)det( DIJh
Asymptotic symmetry is defined to be the transformation group which
preserves the asymptotic structure at null infinity
IJID w.r.t.derivativecovariant :
Asymptotic symmetry
))((2 222 duCdxduCdxhrdudreduAeds JJII
IJ
BB
)/1( ),/1( ),/1( ),/1( 32/222/12/ D
IJ
D
ur
D
rI
D
uu rOgrOgrOgrOg
)(),(),(),(1 )12/(2/)2()12/( D
IJIJ
DIDD rOhrOCrOBrOA
The asymptotic behavior
IJ
K
KJIu
I
IIJ
K
KIJJI
I
uD
fDDfDDfDfD
D
fDfDfDf
2 ,)2(,
2
2 ,0
)/1(2
22
2 e.g., 32/2
D
IJ
K
KJIIJ
K
KIJJIIJ rO
D
fDDfDDr
D
fDfDfDrg
Asymptotic symmetry is Poincare
The asymptotic symmetry is generated by
IJ
K
KJIu
I
IIJ
K
KIJJI
I
uD
fDDfDDfDfD
D
fDfDfDf
2 ,)2(,
2
2 ,0
Iff and
group Lorentz
ntranslatio
If
f
D=4 is special
IJ
K
KJIu
I
IIJ
K
KIJJI
I
uD
fDDfDDfDfD
D
fDfDfDf
2 ,)2(,
2
2 ,0
)/1(2
22
2 32/2
D
IJ
K
KJIIJ
K
KIJJIIJ rO
D
fDDfDDr
D
fDfDfDrg
group Lorentz
ntranslatio
If
f
)/1(, 32/ D
IJ rOg )(rOgIJ
)(rO
+supertranslation
This gives us troublesome when one defines angular momentum at null infinity
4. Application
Stability of BHs
The symmetry which exact BH solutions have are
not enough to analyse the stability.
Together with the general properties of dynamical
BHs, we may be able to have some indications.
Stability of BHs
area)(A
fixed J
Figueras, Murata & Reall 2011, Hollands & Wald 2012
mass)(M
solution a :)(AMM BH
Area theorem
Bondi mass loss
Perturbed initial data
Stable
unstable
Classification
RC nsor Riemann te ofpart free trace
)/1( 5
4
)(
3
),(
2
)()(
rOr
C
r
C
r
C
r
CC
IDIIIIIN
Weyl tensor:
contains information of spacetime(gravity)
Peeling property in 4D
Algebraic classification of Weyl tensor (Petrov type) ⇔ asymptotic behavior
In Type D the equations will be significantly simplified and then
solved completely. The Kerr solution, C-metric ,….
Using our result, a peeling properties has been discussed in higher dimensions
[Godazgar & Reall 2012]. ] odd)[/1(or ]even )[/1( 2/32/22/
12/
)(
2/
)(
12/
)(
DrODrOr
C
r
C
r
CC DD
D
G
D
II
D
N
5 )( Di
5 )( Dii)/1( 4
2/7
)(
3
)(
2/5
)(
2/3
)(
rOr
C
r
C
r
C
r
CC
GNIIN
Classification
Similar to four dimensions, the classification of
the Weyl tensor and the peeling property may
give us a hint to classify and/or construct exact
solutions in higher dimensions.
5. Summary and future issues
Summary
For odd dimensions, we had to solve the Einstein equation
to formulate the asymptotics at null infinity.
We could show the Bondi mass loss law and the presence
of the Poincare symmetry at null infinity.
We also defined the momentum and angular momentum.
There are a few efforts to discuss the stability and
classification of higher dimensional BHs/spacetimes.
Remaining issues
Still…
Stability…
Classification…
Construction…
New issues?
Asymptotically anti-deSitter spacetimes
⇔ always unstable? Final fate? [Dias,Horowitz,Santos,2011]
Asymptotics in spacetimes with compact space
⇔ final fate of black string?
[Latest numerical simulation:Lehner & Pretorius 2010]
YITP Molecule-type workshop on
Non-linear massive gravity
23rd July to 8th August
Core participants :
C. de Rham, S. Mukohyama, …, T.Shiromizu(Chair), A. Tolley, …
Appendix
Constraint and evolution eqs.
In Bondi coordinate,
))((222 duCdxduCdxdudreduAeds JJII
IJ
BB
time u
equations constraint 0 RRr
equations evolution 0,0 IJuu RR
Constraint equations
))((2 222 duCdxduCdxhrdudreduAeds JJII
IJ
BB
JLIK
KLIJrr hhhhD
rBR
)2(4 0
Rr
eBh
r
eBBh
r
e
CCher
Cr
D C
r
ArDR
hB
J
IJ
I
B
JI
IJB
JI
IJ
BI
I
I
ID
D
)(
2
)()(
2
)()(
2
2)()(
2
3
)(2
2
)2(2)()2( 0
IJ
Jh
II
J
IJ
BD
DrI hBr
DBCher
rR
)()()(
2
2)(
1 0
determined are , , surface,const - initial on thegiven are Once I
IJ CBAuh
Constraint equations
))((2 222 duCdxduCdxhrdudreduAeds JJII
IJ
BB
)dimensions oddfor 2 even,for ( 0
)12/()1( ZkZkrhhk
kDk
IJIJIJ
s tracelesis )12/()det( )1(
2
Dkhh k
IJDIJ
)1()1()1(2/3)2()1(
16
1 ),/1( KLIJ
JLIKDD hhBrOrBB
IJk
J
IkDDk
kD
II
kD
IkI h
kDkD
kDCrO
r
xuJ
r
CC )1()()1(2/1
12/
012/
)1(
)22)(2(
)22(2 ),/1(
),(
IJk
JI
kDDk
kD
I
kD
k
hkDkDkD
kDArO
r
xum
r
AA )1()()()1(2/5
22/
0312/
)1(
)42)(22)(2(
)42(4 ),/1(
),(1
Evolution equations
))((2 222 duCdxduCdxhrdudreduAeds JJII
IJ
BB
)dimensions oddfor 2 even,for ( 0
)12/()1( ZkZkrhhk
kDk
IJIJIJ
IJ
k
K
Kk
JI
k
KJ
K
I
k
IJ
k
IJIJ
kk
IJIJ
CCkDhh
hkkDDAkDhkR
)1()()1(
)(
)()1(
)
)(
(
)()1(2)(
)1(22)1()2(
)42(2
1)2(
2
1
)]4(46[8
1)42(
2
1)1( 0
s tracelesis )12/()det( )1(
2
Dkhh k
IJDIJ
)22/(2)()22/()()1()1(
2
1
2
5
)2(2
1 0
DD
I
IIJ
IJuu AD
CD
Dhh
DmR
Asymptotic symmetry
Asymptotic symmetry
))((2 222 duCdxduCdxhrdudreduAeds JJII
IJ
BB
g
u
I
II
I
ur
IJ
IJ
J
IJ
uJ
IJ
u
I
B
rI
uB
rr
Cgg
Ceg
eg
)()(
)(
22)(log)(log
02
)(
)(),(),(1
)12/(
2/)2()12/(
D
IJIJ
DIDD
rOh
rOCrOBrOA
Bondi coordinate condition
)(2
,),(
),,(
2
I
II
Ir
J
IJB
III
Iu
fDfDCD
r
fDhr
edrxuf
xuf
2)det( DIJh
Asymptotic symmetry is defined to be the transformation group which
preserves the asymptotic structure at null infinity
IJID w.r.t.derivativecovariant :
Asymptotic symmetry
))((2 222 duCdxduCdxhrdudreduAeds JJII
IJ
BB
)/1(2
22
2
)/1(])2([2
1])2([
2
)/1()2)(2(
22])2([
2
1
)/1(2
))2((2
2
2
2
32/2)(
)()()(
)(
)(2
22/
32/
)1(2)()(2
2
2/
)()(22/
0
)1()(
12/
22/
)1(2)()(
D
IJJIIJ
K
KJIIJ
D
D
J
uIJIu
I
IIIuuI
D
kD
JIDk
k
k
IJu
I
Iur
D
D
I
uIu
I
Iuuu
rOD
ffr
D
ffrg
rOr
fhfDf
DfDf
D
rfrg
rOr
fh
kDD
kDfDf
Dg
rOr
fCfn
Df
D
rg
)(
)(),(),(1
)12/(
2/)2()12/(
D
IJIJ
DIDD
rOh
rOCrOBrOA
2)det( DIJh
IJ
K
KJIu
I
IIJ
K
KIJJI
I
uD
fffDf
D
ffff
2 ,)2(,
2
2 ,0
)()()()()(
)()()(
Asymptotic symmetry
IJ
K
KJIu
I
IIJ
K
KIJJI
I
uD
fffDf
D
ffff
2 ,)2(,
2
2 ,0
)()()()()(
)()()(
)(2
)( )2(: ,0 )( I
I
u
I
I
I
u xuD
xFffDfFf
IJ
K
KJIIJ
K
KJI
D
FF
D
ff
2
2
)()()()(
)()()()(
0))2(( 2
2 2)()(
)()()()(
FD
D
fff IJ
K
KIJJI
JI
IJ
K
KJIIJ
K
KJI
DD
ff
2
2
)()()()(
)()()()(
2on harmonics
scalar theof modes 1
DS
l
2on harmonics
scalar theof modes 1,0
DS
l
0 ,0 .,., ofpart e transver: )()()()()()()( I
trans
JJ
trans
I
Itrans
I
Itrans fffeiff Lorentz
group
time/space translations
Petrov type
Principal null direction
mnmnCmnnlC
mnmlCmlnlCmlmlC
43
*
210
,
,,,
Five complex functions
0,0,1,1 , ***
nnllmmnlmmmmlnnlg v
null tetrad
Transformation of null tetrad and principal null direction
naamaamllanmmnn ***,,
4
4
3
3
2
2
100 464 aaaa
afor equation thesatisfyingby zero made becan 00464 4
4
3
3
2
2
10 aaaa
I (four distinct roots), II(two coincident ), D(two distinct double),
III(three coincident), N(four coincident)
Petrov classification
I (four distinct roots), II(two coincident ), D(two distinct double),
III(three coincident), N(four coincident)
0 I 10
0 II 410
0 D 4310
0 III 4210
0 N 3210