Determination of cosmological parameters

1. Determination of cosmological parameters Gong-Bo Zhao, Jun-Qing Xia, Bo Feng, Hong Li Xinmin Zhang IHEP, Beijing06.8.30

2. Parameter space Dark energy perturbation ?? Universe encoded in 2nd Sino-French Workshop

3. Outline 1 Dark energy perturbations when w crossing -1 2 Global fitting results of dark energy parameters 3 Dark energy & Inflation 4 Dark energy & neutrino mass limit 5 Bump-like dark energy 6 Searching for CPT violation 2nd Sino-French Workshop

4. Dark Energy: * Negative pressure:  * Smoothly distributed, (almost ) not clustering Candidates: * Cosmological constant (or vacuum Energy) cosmological constant problem! * Dynamical Field: Quintessence, K-essence, Phantom etc 2nd Sino-French Workshop

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6. Feng, Wang & Zhang Astro-ph/0404224 Huterer & Cooray Astro-ph/0404062 w z 2nd Sino-French Workshop

7. 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: * Phantom: * K-essence: or but cannot across -1 (Vikman: astro-ph/0407107 ) A new scenanio of Dark Energy : Quintom (Zhang et al.Astro-ph/0404224) For ex: single scalar: multi-scalar: 2nd Sino-French Workshop

8. Adding CMB,LSS data Astro-ph/0407259, Steen Hannestad, Edvard Mortsell 2nd Sino-French Workshop

9. Include DE perturbation when parametrizing the EOS Ch. Yeche et al Astro-ph/0507170 BIASED! Including DE perturbation only when w>-1 Seljak et al Astro-ph/0407372 Neglect DE perturbations 2nd Sino-French Workshop

10. Strategies to handle the fluctuation of Dark Energy Difficulty: 2nd Sino-French Workshop

11. A way out based on quintom model 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 2nd Sino-French Workshop

12. Our strategy to handle perturbations when w crosses -1 • Quintessence – like perturbation • Phantom – like perturbation • Quintom-based perturbation 2nd Sino-French Workshop

13. 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 2nd Sino-French Workshop

14. Comparision of global fitting results with SN Ia (Riess) and SNLS WMAP+SDSS+SNLS WMAP+SDSS+Riess Jun-Qing Xia, Gongbo Zhao, Bo Feng, Hong Li and Xinmin Zhang Phys.Rev.D73, 063521, 2006 2nd Sino-French Workshop

15. Relative error: ~9% Relative error > 50% !! Constrain on dark energy by WMAP (importance of perturbation) 2nd Sino-French Workshop

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17. Gong-Bo Zhao, Jun-Qing Xia, Bo Feng and Xinmin Zhang, astro-ph/0603621 2nd Sino-French Workshop

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21. A short summary on dark energy • Current data consistent with the cosmological constant • Dynamical models not ruled out • Data mildly favor the Quintom: a dynamical dark energy with • equation of state evolving and crossing -1 • Questions: How dynamical dark energy in the global fitting affects the parameters of inflation, neutrino mass … ? • I. Interesting correlation between Inflation and dark energy parameters • Interesting correlation between dynamical dark energy and neutrino mass 2nd Sino-French Workshop

22. Dark energy & Inflation 2nd Sino-French Workshop

23. WMAP3 + RIESS + SDSS (14 k-bands) 2nd Sino-French Workshop

24. Neutrino mass limit and dynamics of dark energy Jun-Qing Xia, Gong-Bo Zhao, Bo Feng, Xinmin Zhang In preparation 2nd Sino-French Workshop

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28. Bump-like dark energy 2nd Sino-French Workshop

29. EoS with feature: 2nd Sino-French Workshop

30. Probing this feature with GRB?? 2nd Sino-French Workshop

31. “Offline” analysis of the first 2 years - Search the previous year imaging data for likely SNe either missed or not spectred for various reasons - get z from host galaxy spectro (either by us or other projects) or get photo-z from imaging - photo-id the SN - add Ia to the Hubble diagram (in red) very preliminary Z=1.2 ! From Prof. Reynald Pain’s Hangzhou talk (May, 2006) 2nd Sino-French Workshop

32. Precise Hubble diagram from SNe IaFrom Dr. Xiao Feng Wang’s Hangzhou talk ( May, 2006) 2nd Sino-French Workshop

33. Searching for CPT violation 2nd Sino-French Workshop

34. predicting <TB> and <EB> (Note here the notation: G ~ E, C~ B) Bo Feng, Mingzhe Li , Jun-Qing Xia, Xuelei Chen and Xinmin Zhang Phys. Rev. Lett. 96, 221302 (2006) 2nd Sino-French Workshop

35. Summary • Quintom Dark Energy Models: • Current data consistent with the cosmological constant • but mildly favor the Quintom: a dynamical dark energy with • Equation of state evolving and crossing -1 • need more data and model building of Quintom dark energy • Interesting correlation between ns, alphas & DE • Interesting correlation between w1 neutrino mass • A model of Dark energy with featured EOS and its prediction (modulation) • on Hubble diagrams • V. Searching for Cosmological CPT Violation with new CMB data 2nd Sino-French Workshop

36. Thank You ! 2nd Sino-French Workshop