Transcript 幻灯片 1 - The Kavli Institute for Astronomy and
Recent progress on the study of Dark Energy
Xinmin Zhang Institute of high energy physics
Outline
1) Brief review on the models of dark energy, especially on Quintom model; 2) Current constraints on the equation of state of dark energy; 3) Interacting dark energy: a) Neutrino dark energy; b) Cosmological CPT violation and CMB polarization.
1) “Testing CPT Symmetry with CMB Measurements: Update After WMAP5” Jun-Qing Xia, Hong Li, Gong-Bo Zhao & Xinmin Zhang, Astrophys.J. 679:L61( 2008 ).
2) “On using the WMAP distance priors in constraining the time evolving equation of state of dark energy” Hong Li, Jun-Qing Xia, Gong-Bo Zhao, Zu-Hui Fan & Xinmin Zhang, arXiv: 0805.1118, Accepted for publication on Astrophys.J.Letter ( 2008 ).
3) “Determining the cosmological parameters with the latest cosmological observations” Jun-Qing Xia, Hong Li, Gong-Bo Zhao & Xinmin Zhang, in preparation ( 2008 ).
4) “On Perturbations of Quintom Bounce” Yi-Fu Cai, Taotao Qiu, Robert Brandenberger, Yun-Song Piao, Xinmin Zhang, JCAP 0803:013( 2008 ).
5) “Oscillating universe with quintom matter” Hua-Hui Xiong, Yi-Fu Cai, Taotao Qiu, Yun-Song Piao, Xinmin Zhang, arXiv: 0805.0413 ( 2008 )
/
a
a
Negative pressure:
4
G
( 3
p
) 0 3 3
p
Dark Energy:
0
w
p
/ 1 / 3 *
Smoothly distributed, (almost ) not clustering
Candidates: I Cosmological constant (or vacuum Energy)
T
w
p
8
G
/
g
1
p
8
G
( 2 10 3
eV
m ~ ) 4 10 3 eV
th
/
ob
~ 10 120
cosmological constant problem!
II Dynamical Field: Quintessence
L
1 2
Q
Q
V
(
Q
)
Q
1 2 2
V
,
p Q
1 2 2
V
1
w Q
1
Equation of state w=p/ ρ: characterize the properties of the dark energy models * Vacuum : w=-1 * Quintessence:
w
1 Important determining the equation of state of dark energy with cosmological observations
Parameterization of equation of state:
A) w=w_0+w_1 z (for small z) B) w=w_0+w_1 z / (1+z) (used mostly in the literature) C) w=w_0+w_1 sin(w_2 ln(a)+w_3) * * Phantom:
L
Q
2 Quintom: w crosses -1 For example: single scalar:
Q
1 2
Q
2
Q
1 2
Q
2
V w
1
No-Go Theorem!!
No-Go Theorem:
For theory of dark energy (DE) in the 4D Friedmann-Robertson-Walker (FRW) universe described by a single perfect fluid or a single scalar field with a lagrangian of , which minimally couples to Einstein Gravity, its equation of state w cannot cross over the cosmological constant boundary.
Examples of Quintom models: 1) Two scalar fields: 2) Single scalar with high derivatives: 3) Modified Born-Infeld action:
V
( )
e
V
0
e
,
Comments on Quintom model: 1) Quintom Bounce
The expanding of the universe is transited from a contracting phase; during the transition the scale factor of the universe a is at its minimum but non-vanishing, thus the singularity problem can be avoided.
20 Contracting phase ：
H
0 ； Expanding Phase:
H
0 .
18 16 14 At the boun cing point:
H
0
Around it:
H
0 .
a
12 10 8
H
4
G
(
p
)
w
1 6 4 Transition to the observable universe So w needs to cross -1, and Quintom matter is required ！
w
(radiation dominant, matter dominant,…) 1 .
2 0 -10 -8 a=1 -6 -4 -2 0
t
2 4 6 8 10
Yifu Cai et al., JCAP 0803:013(2008).
Yifu Cai et al., JHEP 0710:071(2007).
Examples:
1) Two Field Quintom
Examples:
1) A single scalar with high-derivative term
2) Oscillating universe with Quintom matter
Xiong et al., arXiv:0805.0413
Solution:
3) on dark energy perturbation Relative error: ~9% Relative error > 50% !!
Importance of perturbation: Constraint on dark energy by WMAP3
Difficulty with dark energy perturbation when w crosses -1
1
w
0 , 0 , , ,
Perturbation with Quintom dark energy
Here δ and θ are the density perturbation and the divergence of the fluid velocity respectively
Perturbation of DE is continuous during crossing!
Zhao et.al Phys.Rev.D 72,123515,2005
I.
II.
III.
Our strategy to handle perturbations when w crosses -1
Quintessence – like perturbation Phantom – like perturbation Quintom-based perturbation
Constrains on dark energy with SN Ia + SDSS + WMAP-1 Observing dark energy dynamics with supernova, microwave background and galaxy clustering
Jun-Qing Xia, Gong-Bo Zhao, Bo Feng, Hong Li and Xinmin Zhang
Phys.Rev.D73, 063521, 2006
Current constraint on the equation of state of dark energy Quintom A Quintessece Phantom Quintom B WMAP5 result E. Komatsu et al., arXiv:0803.0547
Xia, Li, Zhao, Zhang, in preparation Difference: Data: SN (SNLS+ESSENCE+Riess et al.) vs SN (307,Kowalski et al., arXiv:0804.4142) Status: 1) Cosmological constant fits data well; 2) Dynamical model not ruled out; Method: WMAP distance prior vs Full CMB data.
However, results similar (Li et al., arXiv: 0805.1118) 3) Best fit value of equation of state: slightly w across -1 Quintom model
Interacting Quintessence
* If Quintessence –like scalar field responsible for the current acceleration of the Universe ,expected also to interact with the matter directly.
Open new possibilities for the detection.
* Direct coupling with ordinary matter Constraint from the limits on the long-range force * Interaction with derivative Goldstone theorem: Spin-dependent force a unified model of DE and Baryo(Lepto)genesis Quintessino as DM * Interacting with DM (Peebles et al ) * Interacting with neutrinos: mass varying neutrino
Example of Interacting Dark Energy
QF
F
Variation of the Fine Structure Constant
Q
ll
M Q N R c N R
Neutrino Dark Energy
m
Connection with Neutrino: 1. ΛCDM: ( 10 3
ev
) 4 (
m
) 4
m Q
10 33
eV
m
2
M pl
Gu, Wang, Zhang
，
PRD68, 087301 (2003) Fardon, Nelson, Weiner, JCAP 0410:005(2004)
Neutrino can decay Xiao-Jun Bi, Bo Feng, Hong Li, Xinmin Zhang, PRD72:123523,2005 Neutrino oscillations as a probe of dark energy D. Kaplan, A. Nelson, N. Weiner, Phys.Rev.Lett.93:091801,2004 GRB: Delay of flight time ？ Li, Dai, Zhang, PRD71:113003,2005 Relaxing the cosmological limit on the Neutrino mass Gong-Bo Zhao, Jun-Qing Xia, Xin-Min Zhang, JCAP 0707:010,2007
Interacting Dark Energy CPT Violation, Baryo-/Leptogenesis and CMB Polarization Derivative couplings:
A unified model of dark energy, dark matter and baryon matter 1) A unified model of baryogenesis and dark energy ----Quintessential baryo/leptogenesis 2) When SUSYing, Quintessino is dark matter particle ----A unified model of dark matter and dark energy 3) Probing CPT violation with WMAP and Boomerang
Quintessential Baryo(Lepto)genesis
M.Li, X.Wang, B.Feng, X. Zhang PRD65,103511 (2002) De Felice, Nasri, Trodden, PRD67:043509(2003) M.Li & X. Zhang, PLB573,20 (2003)
n B
L
int 6
c g b T
3
Q J B
In thermo equilibrium
M
[
b
b T
n b
O
(
g
2
b
2
b T
) 3 ]
m
E
(
E
c g b
2
T
6
M
2
Cohen & Kaplan m
2 ) 1 / 2
dE
[ 1 exp[( 1
E
b
) /
T
] 1 exp[(
E
1
b
) /
T
] ]
s
2 2 45
g
T
3
n B
/
s
15
c
4 2
g b g
MT
The value of depends on the model of Quintessence Cosmological CPT violation!
Leptogenesis Anomaly for CMB
Cosmological CPT violation:
predicting
Q
Hong Li et al Bo Feng, Hong Li, Mingzhe Li and Xinmin Zhang Phys. Lett. B 620, 27 (2005); Bo Feng, Mingzhe Li , Jun-Qing Xia, Xuelei Chen and Xinmin Zhang Phys. Rev. Lett. 96, 221302 (2006)
1)
6 .
0 4 .
0 deg
2)
Wavelet Analysis
: WMAP3(TT,TG,GG,CC,TC,GC) Bo Feng et al., PRL 96, 221302 (2006) P.Cabella, Natoli & Silk, PRD76, 123014 (2007) 3)
6 .
2 3 .
8 deg
4) J.Q.Xia et al., arXiv:0710.3325
1.7
2.1 deg
5) Komatsu et al., arXiv:0803.0547
J.Q.Xia et al., arXiv:0803.2350
6)
PLANCK
: 0.057 deg
Quintessino As Dark Matter
•If susying the Quintessence: Quintessence: Q Squintessence: σ q Quintessino: (X. Bi, M. Li and
Zhang)
Similar to : Axion, Saxion, Axino Majoron, Smajoron, Majorino
(R. Mohapatra and Zhang)
•Susying the following interaction (H: SU(2) doublet) gives gives * Prediction: long-lived charged particle:
Summary
1) Current status on constraints on dark energy: a) Cosmological constant fits data well; b) Dynamical model not ruled out; 2) Quintom model: w crosses -1; Bounce with Quintom matter; 3) Interacting dark energy: Neutrino dark energy Mass Varying Neutrino; Cosmological CPT violation; test with CMB; Quintessential Baryo-/Leptogenesis; Quintessino as dark matter.