On the Nature of Dark Matter and Dark Energy Orfeu Bertolami

On the Nature of Dark Matter and Dark Energy Orfeu Bertolami

On the Nature of Dark Matter and Dark Energy
Dark Energy – Dark Matter x Modified Gravity
Orfeu Bertolami
Instituto Superior Técnico
Departamento de Física
(http://alfa.ist.utl.pt/~orfeu/homeorfeu.html)
From Quantum to Cosmos:
Fundamental Physics Research in Space
21-24 May 2006, Warrenton, Virginia, USA
General Relativity
( = =1 )
•
GR has survived all tests so far…
[C. Will, gr-qc/0510072; S. Turyshev, M. Shao, K. Nordtvedt, gr-qc/0601035]
[O.B., J. Páramos, S. Turyshev, gr-qc/0602016]
•
Parametrized Post-Newtonian Formalism (U-gravitational potential,
g 00 = 1 + 2U
•
2 U 2 + ..., g ij = (1 + 2 U )
ij
vi
velocity)
+ ..., g 0i = 1 (4 + 3)vi + ...
2
Local (solar system) tests
Mercury´s perihelion shift:
Lunar Laser Ranging: 4
LBLI light deflection:
Cassini Experiment:
2
1 < 3 ×10
3
[Shapiro 1990]
3 = (4.4 ± 4.5) × 10 4 [Williams, Turyshev, Boggs 2004]
1 < 4 × 10
4
1 = ( 2.1 ± 2.3) ×10
[Eubanks et al. 1997]
5
[Bertotti, Iess, Tortora 2003]
(Partially) Unconfirmed predictions:
Gravitational waves – PSR B1913+16
(LIGO, …, LISA)
Lense-Thirring Effect
(Gravity Probe-B)
Cosmological Tests of General Relativity
•
Outstanding challenges (GR + Quantum Field Theory)
– Singularity Problem
– Cosmological Constant Problem
– Underlying particle physics theory for Inflation
•
Theory provides in the context of the Big Bang model an impressive
picture of the history of the Universe
2
– Nucleosynthesis
(N <4 ,
B h = 0.023 ± 0.001 )
– Cosmic Microwave Background Radiation
– Large Scale Structure
– Gravitational lensing
– …
•
Required entities (missing links):
– Dark Matter
– Dark Energy
Dark Matter
•
Evidence:
Flatness of the rotation curve of galaxies
Large scale structure
Gravitational lensing
N-body simulations and comparison with observations
• Cold Dark Matter (CDM) Model
Weakly interacting non-relativistic massive particle at decoupling
• Candidates:
Neutralinos (SUSY WIMPS), axions, scalar fields, self-interacting scalar
particles, etc.
Dark Energy
•
Evidence:
Dimming of type Ia Supernovae with z > 0.35
a&&a
a& 2
Accelerated expansion (negative deceleration parameter): q 0
[Perlmutter et al. 1998; Riess et al. 1998, …]
•
Homogeneous and isotropic expanding geometry
Driven by the vacuum energy density
and matter density
Equation of state:
•
p=
M
1
Friedmann and Raychaudhuri equations imply:
q0 =
1
(3 + 1)
2
m
q0 < 0 suggests that an invisible smooth energy distribution
•
Candidates:
Cosmological constant, quintessence, more complex equations of state,
etc.
0 . 47
Supernova Legacy Survey (SNLS)
[Astier et al., astro-ph/0510447]
SNLS - SDSS
[Riess et al. 2004]
= 1.02 +00..13
19
[Astier et al. 2005]
= 1.023 ± 0.090( stat ) ± 0.054( syst )
m
= 0.271 ± 0.021( stat ) ± 0.007( syst )
WMAP 3 Year Results
D.N. Spergel et al., astro-ph/0603449
WMAP 3 Year Results
D.N. Spergel et al., astro-ph/0603449
WMAP 3 + SNLS:
=
p
WMAP 3 Year Results
D.N. Spergel et al., astro-ph/0603449
Gamma-ray bursts and Dark Matter
Effect of the increase of high red shift GRBs (90, 500, 1000) for XCDM models
[O.B., Silva, M.N.R.A.S. 2006]
A Universe dominated by dark components
Cosmic Concordance
(PCDM)
QP
0.72
Qm
0.28
Qk
0
Quintessence
Varying vacuum energy models
[Bronstein 1933; O.B. 1986; Ratra, Peebles 1988; Wetterich 1988; …]
• V0 exp (-
)
[Ratra, Peebles 1988; Wetterich 1988; Ferreira, Joyce 1998]
>0
[Ratra, Peebles 1988]
• V0
-
,
• V0
-
exp (
2
• V0 [exp ( Mp /
),
[Brax, Martin 1999, 2000]
)–1]
• V0 ( cosh
- 1 )p
• V0 sinh- (
)
• V0 [ exp (
>0
[Zlatev, Wang, Steinhardt 1999]
[Sahni, Wang 2000]
[Sahni, Starobinsky 2000; Urena-López, Matos 2000]
) + exp (
)]
[Barreiro, Copeland, Nunes 2000]
• Scalar-Tensor Theories of Gravity
[Uzan 1999; Amendola 1999; O.B., Martins 2000; Fujii 2000; ...]
• V0 exp( -
)[A+(
- B )2 ]
• V0 exp( -
)[a+(
-
0
)2 + b (
[Albrecht, Skordis 2000]
-
0
)2 + c
(
-
0
)2 +d
(
-
0
)2 ]
[Bento, O.B., Santos 2002]
Eternally accelarating expansion
Spacetime has future horizons
Problem for string/M-theory S-matrix (asymptotically flat Minkowski spacetime)
[Hellerman, Kaloper, Susskind; Fischler, Kashani-Poor, McNess, Paban; Witten 2001]
Possible Solution: transient acceleration
Dark Energy and Dark Matter
“Quintessential Inflation”
[Peebles, Vilenkin 1999; Dimopoulos, Valle 2002; O.B., Duvvuri 2006, …]
Inflation
Dynamics
DE
DM
Dark Energy – Dark Matter interaction
[Amendola 2000]
Dark Energy – Dark Matter Unification
[Kamenschik, Moschella, Pasquier 2001]
[Bilic, Tupper, Viollier 2002; Bento, O.B., Sen 2002]
Generalized Chaplygin gas
model
•
Unified model for Dark Energy and Dark Matter
Generalized d-brane
Generalized Chaplygin gas
: d-brane
Dust
: Chaplygin gas
: stiff matter
[Kamenschik, Moschella, Pasquier 2001]
[Bilic, Tupper, Viollier 2002; Bento, O.B., Sen 2002]
De Sitter
Dark Energy - Dark Matter Unification:
Generalized Chaplygin Gas Model
–
CMBR Constraints
–
SNe Ia
–
Gravitational Lensing
[Bento, O. B., Sen 2003, 2004; Amendola et al. 2004]
[O. B., Sen, Sen, Silva 2004; Bento, O.B., Santos, Sen 2005]
[Silva, O. B. 2003]
– Structure Formation
[Sandvik, Tegmark, Zaldarriaga, Waga 2004; Bento, O. B., Sen 2004; Bilic, Tupper, Viollier 2005; …]
– Gamma-ray bursts
[O. B., Silva 2006]
– Cosmic topology
Background tests:
[Bento, O. B., Rebouças, Silva 2006]
0.6, 0.75 As
0.85
As
A
1+
Ch 0
Possible solutions for the structure formation problem:
• Truncation of the phantom contribution
[Bento, O.B., Sen 2004]
• Chaplygin-Kalb-Ramond Quartessence:
nonadiabatic energy density perturbations
[Bilic, Tupper, Viollier 2005]
• Observational Constraints Silent Quartessence:
nonadiabatic energy density fluctuations ( 0.3 <
[Amendola, Waga, Finelli 2005]
< 0.7 )
Density constrast !(aeq) for different values
of , as compared with CDM.
[Bento, O. B., Sen 2002]
The growth factor m(y) as a function of the
scale factor a. The solid, dotted, dashed and
dash-dot lines correspond to = 0, 0.2, 0.4,
0.6 respectively. It is assumed:
= 0.2
dm0 = 0.25,
0 = 0.7,
b0 = 0.05 and
The bias b as a function of the scale factor a.
The solid, dotted, dashed and dash-dot lines
correspond to = 0, 0.2, 0.4, 0.6 respectively.
It is assumed: dm0 = 0.25,
0 = 0.7,
= 0.2
b0 = 0.05 and
[Bento, O. B., Sen 2004]
Pioneer 10 as a Probe
Pioneer 10/11 anomalous deceleration (20 AU – 70 AU):
aPio = (8.5 ± 1.3) ×10
10
m / s2
[Anderson, Laing, Lau, Liu, Nieto, Turyshev 2002]
Cause:
Systematical effects ?
Thermal effects ?
[Scheffer 2003]
Kuiper Belt gravity ? No !
[Anderson et al. 2002, Nieto 2005, O.B., Vieira 2005]
Scalar field ?
[O.B., Páramos 2004]
Post-Newtonian model with running coupling consts. ?
[Jaekel, Reynaud 2005]
…
Deceleration due to dragging:
a Pio = O(1)
2
Med . Pio
v APio
mPio
vPio = 11.6 12.2km / s, APio = 5.9m 2 , mPio = 241kg
DM
DE
DM
DE
6 ×10
Halo
6 × 10
30
24
g / cm3
g / cm3
aDM
aDE
2 × 10
Med .
= 3 ×10
2 × 10 5 a Pio
11
a Pio
19
g / cm3
A Mission to Test the Pioneer Anomaly
Dittus et al., gr-qc/0506139
Direct Dark Matter Detection
[Baudis 2005]
Self-Interacting Dark Matter
[Spergel, Steinhardt 2000]
Motivation: “cuspy core” problem
Model:
Higgs decay width
[Bento, O.B., Rosenfeld, Teodoro 2000]
[Siveira, Zee 1988]
[Bento, O.B., Rosenfeld 2001]
[Bento, O.B., Rosenfeld 2001]
Direct Dark Energy Detection ?
• Spectrum noise in Josephson junctions
h
c3
4
c
DE
GeV
= (3.9 ± 0.4) 3
m
c
[Beck, Mackey 2005]
(1.69 ± 0.05) × 1012 Hz
• No! Zero-energy fluctuations are not measurable …
[Jetzer, Straumann 2005]
• DE-gauge field coupling: variation of the “fine structure constant”
[Olive, Pospelov 2002; Gardner 2003; …]
[O.B., Lehnert, Potting, Ribeiro 2003; Bento, O.B., Santos 2004]
Variation of the electromagnetic coupling via direct Q-electromagnetic interaction
[Olive, Pospelov 2002; Gardner 2003; …]
[O.B., Lehnert, Potting, Ribeiro 2003; Bento, O.B., Santos 2004]
Meteorites
Oklo
[Bento, O.B., Santos 2004]
Large Dark Energy Surveys
SNAP, DUNE…
Supernovae
Standard Candles
Luminosity Distance
Cosmic Shear Evolution of DM perts.
Baryon Acoustic Oscillations
Standard ruler
Angular diameter distance
Dark Matter
Modified Newtonian
Dynamics (MOND)
[Milgrom 1983, Bekenstein, Milgrom 1984, ..., Bekenstein 2004]
Motivation: Flatness Rotation Curve of Galaxies
a0 ( 1.2 × 10-10 m/s2 - universal acceleration
Tully-Fisher Law:
as
TeVeS2 version: F-function problem
MOND
Tensor-Vector-Scalar field theory, S = Sg + Ss + Sv + Sm:
Conformal transformation to the physical metric:
Consistency
• PPN:
= 1, = 1
i) (Potentially) compatible
[Skordis, Mota, Ferreira, Boehm 2005]
• CMBR
ii) Problem with the third peak
[Slosar, Melchiorri, Silk 2005]
P CDM
PMOND
2×10 2
• Gravitational lensing – great potential for testing
[Zhao, Bacon, Taylor, Horne 2005]
Dark Energy
Self-accelerating
gravity models
[Dvali, Gabadadze, Porrati 2000; Deffayet 2001; Freese, Lewis 2002; … ]
Motivation: 5D Braneworlds
E.g. BPS-branes (Randall-Sundrum, Dilatonic): bulk scalar field
U=
2
1
PPN:
4
3
1=
1=
1
9
(
2
2
[Palma 2006]
2
1
)
Self-accelerating gravity models
• “Infrared” Modifications of Gravity (rc= 3 Gpc – crossover constant):
• PPN:
= 1, = 1
• Lense-Thirring effect unchanged
• DGP
• DT
• Cardassian
[Iorio 2006]
[Dvali, Gabadadze, Porrati 2000]
[Deffayet 2001]
[Dvali, Turner 2003]
[Freese, Lewis 2002]
DGP model
5D action:
(M, R5) and (Mp, R), 5D and 4D Planck masses and scalar curvatures
Non-gravitational interactions on the brane:
5D Minkovski space and 4D metric:
Gravitational potential (
Long range (5D propagation):
Short range:
):
Cosmological Constraints
[Bento, O.B., Rebouças, Santos 2006]
Cosmological Constraints
• Baryon Acoustic Oscillations
LRG (SDSS):
• CMBR Shift Parameter (
WMP 3:
[Eisenstein et al. 2005]
)
Scalar-Tensor Theories of Gravity
Binary Pulsars (B1913+16; J1141-6545)
1=
1=
2
1+
2
0
(1 +
0
1
< 1.1
1
2
0
0
2 2
0
)
[Esposito-Farese 2004]
0
< 0.060,
0
> 4.5
Conclusions
•
Cracking the puzzles of DE and DM will require a concerted effort:
-
WIMPs may be detected in colliders or underground detectors
-
Axion detected ?
-
Space based experiments to observe SNe (SNe “factories”), gammaray bursts, gravitational lensing, cosmic shear, etc, are the most likely
way to characterize the properties of DE and DM, or alternatively, to
find evidence for the inadequacy of General Relativity
-
Further testing General Relativity and examining the implications of its
contending theories or extensions (scalar-tensor theories, braneworld
models, strings) must be pursued through a whole new programme of
dedicated space experiments
[Zavattini et al. 2006]
Alone in the dark?
Orfeu Bertolami
Lisbon, Portugal
From Quantum to Cosmos:
Fundamental Physics Research in Space