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HaengDang Symposium 2007 - Recent Studies in Astro-Particle Physics - Nov. 30.(Fri.) 2007. The false vacuum bubble : - formation and evolution -. Wonwoo Lee Sogang University. in collaboration with - PowerPoint PPT Presentation
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The false vacuum bubble :
- formation and evolution -
in collaboration withBum-Hoon Lee, Chul H. Lee, Siyong Nam, and Chanyong Park
Based on PRD74, 123520 (2006), PRD75, 103506 (2007), arXiv:0710.4599 [hep-th]
Wonwoo LeeSogang University
HaengDang Symposium 2007- Recent Studies in Astro-Particle Physics
- Nov. 30.(Fri.) 2007
The plan of this talk1. Motivations, 2. False vacuum bubble nucleation due to a
nonminimally coupled scalar field 1) Numerical calculation 2) Thin-wall approximation
3. The dynamics of a false vacuum bubble : the junction equations
4. Summary and discussions
1. Motivations -I
What is the origin of our universe?
1) Is our universe created from nothing?
2) Is our universe created from something?
3) Can the universe create itself?
1. Motivations -II(1) What did the spacetime look like in the very early universe? - Wheeler’s spacetime foam structure - The cosmological constant as a dynamical variable Can we obtain the mechanism for the nucleation of a false vacuum bubble? Can a false vacuum bubble expand within the true vacuum background?
(2) The idea of the string theory landscape has a vast number of metastable vacua. Which mechanism worked to select our universe in this landscape?
Can we be in the vacuum with positive cosmological constant ?(through an alternative way to KKLT, for example)
2. The Einstein theory of gravity with a nonminimally
coupled scalar fieldVacuum-to-vacuum phase transition rate
Action
Einstein equations
/ exp[ / ]V A B
4 21 1[ ( )]2 2 2RS gd x R U
12
R g R T
2 22
1 1[ ( ) ( )]1 2
T g U g
boundaryS
curvature scalar
Potential
Rotationally invariant Euclidean metric : O(4)-symmetry
The Euclidean field equations
boundary conditions
2 2( ) ( 2 ) ( 2 )8 2 oU b b U
b
2 2 2 2 2 2 2 2( )[ sin ( sin )]ds d d d d
2
2
1]3)(4[
U
R
3 ''' ' EdURd
22 2
2
1' 1 ( ' )3(1 ) 2
U
0|,)( 0(max)
lim
dd
T
Our main idea
(during the phase transition)
3 ' 'ER
1) Numerical calculation(Case 1) from de Sitter to de Sitter
(Case 2) from flat to de Sitter
(Case 3) from anti-de Sitter to de Sitter
(Case 4) from anti-de Sitter to flat
(Case 5) from anti-de Sitter to anti-de Sitter
False-to-true True-to-falseDe Sitter – de
Sitter O O
Flat – de Sitter O OAnti-de Sitter –
de Sitter O OAnti-de Sitter –
flat O OAnti-de Sitter – Anti-de Sitter O O
2)Thin-wall approximation
B is the difference
In this approximation
Outside the wall
b TE EB S S
in wall outB B B B
( ) ( ) 0out E T E TB S S
In the wall
where
inside the wall
dUUS F
TTo )]()([2
412 4(1 2ln )b bC
22 2 3/ 2
22
2
( )(1 ) {[1 ] 1}3(1 )12 [ ( )]( )
FF
Fin F T
F
U
BU
),(2 232
CSB owall
(a) false vacuum bubble nucleation
if
6816
3)2(4
4)82( 242
22 CSbbUUbSbH oo
oo
23
83
83
281
29
222222ooooo SUbUbUSE
38256
3264
2364 CSbbCSbD oo
22 H H ED
E
o
4
2
2
1
22
2221
oo
op
/3 oo S )](/3[21 TF UU 2
2 [3/ ( )]F TU U
The coefficient B
(b) true vacuum bubble nucleation
1
)41(31)41(1
31112
2/3
22
2222/32
2
2
bU
UbU
UB T
T
F
F
6816
3)2(4
4)82( 1242
22
1 CSbbUUbSbH oo
oo
38256
3264 1
23614
1 CSbbCSbD oo
23
83
83
281
29
222222ooooo SUbUbUSE
)
4ln21(12
41
bbC
EEDHH 1
2112
1
The coefficient B
if (by S. Parke)
where
o
4
2
2
1
22
2221
oo
op
13
11)41(3
11)41(122/322/3
22
222
2
2F
F
T
T
UUb
UUbB
2/14
2
2
1
2
1
2
4
2
2/14
2
2
1
2
1
22211
2
2221
212
ooo
oooo
p
B
B
342 2/27 oo SB
Two types related to this formalism
(1) Boundary surface
(2) Surface layer In this case it is related to the discontinuity of the extrinsic curvature of the surface. We consider thin-wall partitions bulk spacetime into two distinct manifolds
and with boundaries and , respectively. To obtain the single glued manifold
we demand that the boundaries are identified as follows:
0ijS
0ijS
3. The dynamics of a false vacuum bubble : the junction
equations
M
M MMM
We consider the action
where
In this framework, junction condition becomes
or
where , a effective negative tension of the wall
There are parameter regions including that both and are positive in all ranges of
4 21 1[ ( )]2 2 2RS gd x R U
twSKxdh )1( 23
),(3
UxdhStw,8 G gg det
rHrHr21)1( 222
)(21 _
22
rHrHr
Hr
r2
2_ 2
,1)( 2rAinH rGMrAoutH 21)( 2
r
After squaring twice, the equation turns out to be
where the effective potential is
with
PPQTT
rVeff 2)(
2
0)(21 2
rVr eff
222
2
22422222
222222222
222222222
42222222
222222222
22222222
])1(1[
,4)1(4)1]()1(1[
])1(1[4)1](41)1[(
}21]
41)1][()1(1{[2
}]41)1{[(
,}21]
41)1][()1(1{[
)1(])1(1[2])1(1[
PrMG
rGM
GMrAA
rAA
rAAAQ
rAA
rGMT
(1) M = 0
DS – DS
DS – FLAT
DS – ADS
(2) M > 0
DS – SDS
DS – S
DS – SADS
ER
4. Summary and Discussions• The false vacuum bubble can be nucleated within the true vacuum background with a nonminimally coupled scalar field• expect the phenomenon be possible in many other theories of gravity with similar terms. • A false vacuum bubble with minimal coupling, without singularity in their past, can expand within the true vacuum background with nonminimal coupling.• An expanding false vacuum bubble is not inside the horizon of a black hole from outside observer’s point of view. • Can it be a model for the accelerating expanding universe?
Thank you for
your attention!