Dark energy and its connections to ne utrino, baryo/leptogenesis and dark matter Xinmi n Zhang Institute of High En ergy Physics Beijing Outli ne of the talk I. Current status on determination of th e equation of state of dark energy an d Quintom Model II.Interacting dark energy and mass vary ing neutrino
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Dark energy and its connections to neutrino, baryo/leptogenesis and dark matter Xinmin Zhang
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Dark energy and its connections to neutrino, baryo/leptogenesis and dark matter
Xinmin Zhang Institute of High Energy Physics Beijing Outline of the talkI. Current status on determination of the equation of state
of dark energy and Quintom ModelII. Interacting dark energy and mass varying neutrino
III. A unified model of dark energy, dark matter and baryo
A quantity characterizing the property of Dark Energy:
Equation of state: w(Z)=P/ρ
For example :
* Vacuum Energy: w=-1
* Quintessence:
* Phantom:
Using the recent 157 Supernova data
published by Riess et al. (astro-ph/0402512)
* Within 2 σ, the cosmological constant fits well the data
* Data mildly favors a running of the W across -1
Model independent analysis with the following parameterization: 1 , w(z)=w_0 + w_1* z
2 , w(z)=w_1 + w_a*z/(1+z)
Feng, Wang & Zhang
Astro-ph/0404224
Huterer & Cooray
Astro-ph/0404062
z
w
Implication in model building of dark energy If the running of w(Z), especially a transition across –1, confirmed
in the future, big challenge to the model building
* Vacuum : w=-1
* Quintessence: ( 精质 )
* Phantom: (幽灵) * K-essence: or but cannot across -1 A new scenario of Dark Energy : Quintom (精灵) (Zhang et al. Astro-ph/0404224) For ex:
single scalar:
multi-scalar:
Quintom Model building: Why challeQuintom Model building: Why challenges?nges?No-Go Theorem:No-Go Theorem: Equation of State W can not Equation of State W can not cross over w=-1 if the following cross over w=-1 if the following conditions are satisfied:conditions are satisfied:
I. Einstein GravityII. Minimal CouplingIII. Single Scalar Field IV. Without higher derivative
Examples of Quintom-like Models: 1. two scalar field 2. single scalar field with higher derivative 3. including vector field …… 4. Nonminimal Coupling ……..
Vikman Phys. Rev. D 71, 023515 (2005)Gong-Bo Zhao et al. astro-ph/0507482
Bo Feng et al. astro-ph/0404224
…….Hao Wei, PhD Thesis
Detailed study on: Two-field models of Quintom Dark Energy -Xiao-fei Zhang ,Hong Li, Yunsong Piao and Xinmin Zhang
I. Quintom model with two scalar fields:
II. Quintom model with Phantom field and neutrino:
Astro-ph/0501652
Quintom with Single scalar field and Higher Derivative
Forequivalent to two fields
Mingzhe Li, Bo Feng, Xinmin Zhang, hep-ph/0503268
astro-ph/0407259, Steen Hannestad, Edvard Mortsell
Adding CMB,LSS data
Include DE perturbation when Include DE perturbation when parametrizing the EOSparametrizing the EOS
Seljak et alAstro-ph/0407372
Ch. Yeche et alAstro-ph/0507170
Neglect DE perturbations
Including DE perturbation only when w>-1
BIASED!!
How to calculate the How to calculate the fluctuationfluctuation of Dark Energy ?? of Dark Energy ??
Difficulty:Difficulty:
, 0 ,1 ww
Perturbation of DE continuous never diverge!
Zhao et.al PRD 72,123515
Dark Energy Perturbation in two-field Quintom model
Our strategy to handle perturbations Our strategy to handle perturbations when w crosses -1 for parametriz when w crosses -1 for parametriz
ed EOSed EOSI. Quintessence – like perturbation;
II. Phantom – like perturbation;
III.
1)(zw
1)(zw
1)(1 zw
0 ,0
Constrains on dark energy with SN Ia (Riess) + 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
Jun-Qing Xia, Gongbo Zhao, Bo Feng, Hong Li and Xinmin Zhang Phys.Rev.D73, 063521, 2006
)1/(*1 zzwww 0
WMAP+SDSS+Riess WMAP+SDSS+SNLS
Comparision of global fitting results with SN Ia (Riess) and SNLS
Constrain on dark energy by WMAP group (importance of perturbation)
Current constrains on dark energy1. Cosmological constant fit the data well
2. Dynamical model are not ruled out
3. Quintom is mildly favored
Short summary :
Features of Quintom ( “ 精灵 ” ) Dark Energy Model
I. Challenges to Model building: A lot of recent studies on the models of Dark Energy with equation of state across -1
II. Dark energy perturbation well defined: Implications in CMB, LS
S ……
III. Different from cosmological constant, Quintessence and Phantom in the determination of the evolutions and the fate of the universe
Oscillating Quintom
Oscillating Quintom and the Recurrent Universe: astro-ph/0407432 Bo Feng, Minzhe Li, Yunsong Piao, Xinmin Zhang
Parameterization: Astro-ph / 0605366
Bump-like dark energyBump-like dark energy
EoS with feature:
Probing this feature with GRB??
Precise Hubble diagram from SNe IaPrecise Hubble diagram from SNe Ia From Dr. Xiao Feng Wang’s Hangzhou talk ( May, 2006)From Dr. Xiao Feng Wang’s Hangzhou talk ( May, 2006)
Interacting Dark Energy
Current data favors Quintom
Quintom Dark Energy is described by dynamical scalar fields
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
* Interacting with DM (Peebles et al )
* Interacting with neutrinos ---Mass varying neutrinos