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Determining cosmological parameters with the latest observational data Hong Li TPCSF/IHEP 2009.3.16
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The cosmological observations play a crucial role in understanding universe ! CMB 、 LSS and SN Complementary, GRB and WL also make interesting progress ! Recent years Cosmology became more and more accurate There are also some ongoing ………
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outline The global fitting analysis The constraints on cosmological parameters, especially the time evolving EOS of DE with CMB, LSS, SNe Constraints on EOS including GRBs & WL Testing the featured P(k) with observations Summary
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Global fitting procedure Cosmological parameters: Method : modified CosmoMC, Perturbation included G.-B. Zhao, et al., PRD 72 123515 (2005) Calculated at ShangHai Supercomputer Center (SSC) Data: CMB, LSS, SNe ……. 1.w = constant 2. Perturbation divergent when w across -1, new method 3.
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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 The importance of DE perturbation!
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2007.6.5 IHEP Constraints on EOS with WMAP3 Relative error: ~9% Relative error > 50% !! * Emphasizing the importance of the perturbation of DE * A constant EOS considered by the WMAP group
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Quintessece Quintom A Quintom B Phantom Current constraint on the equation of state of dark energy WMAP5 result E. Komatsu et al., arXiv:0803.0547 Xia, Li, Zhao, Zhang, PRD. 78, 083524 Status: 1) Cosmological constant fits data well; 2) Dynamical model not ruled out; 3) Best fit value of equation of state: slightly w across -1 Quintom model Difference: Data: SN (SNLS+ESSENCE+Riess et al.) vs SN (307,Kowalski et al., arXiv:0804.4142) Method: WMAP distance prior vs Full CMB data. However, results similar (Li et al., arXiv: 0805.1118)
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APJ Lett. 683, L1, 2008
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For the published version : WMAP5 result E. Komatsu et al., Astrophys.J.Suppl.180:330-376,2009 Xia, Li, Zhao, Zhang, PRD. 78, 083524
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Preliminary results With the new CFA (SN), CBI and QUaD data:
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Global analysis of the cosmological parameters including GRBs Results from the global analysis with WMAP3+LSS+SNe(Riess 182 samples)+GRBs (Schaefer 69 sample) New method for solution of the circulation problem
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the 69 modulus published by Schaefer (in astro-ph/0612285)
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Bias with only GRB Need global analysis
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Hong Li, M. su, Z.H. Fan, Z.G. Dai and X.Zhang, astro-ph/0612060, Phys.Lett.B658:95-100,2008 WMAP3+LSS+SN WMAP3+LSS+SN+GRB
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The relevant papers on studies with GRBs : E.L.Wright astro-ph/0701584 F.Y. Wang, Z. G. Dai and Z. H. Zhu, astro-ph/0706.0938
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Problems: The circulation problem : Due to the lack of the low-redshift GRBs, the experiential correlation is obtained from the high- redshift GRBs with input cosmology !
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S_r: is the fluence of the r-ray; t_j: is the Break time; n: is the circumburst particle Density; E_peak: is the peak energy of the spectrum What is the circulation problem? Due to the lack of the low-redshift GRBs, the experiential correlations are obtained from the high-redshift GRBs with input cosmology which we intend to constrain, it lead to the circulation problem! From the observation, we can get: S_r, E_peak,t_j, n With a fire ball GRB model: Ghirlanda et al.
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Usually Input a cosmology Get A & C
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A new method for overcoming the circulation problem for GRBs in global analysis We integrate them out in order to get the constraint on the cosmological parameter: We let A and C free: We can avoid the circulation problem ! And method can apply to the other correlations. Correlation as an example: We take Hong Li et al., APJ 680, 92 (2008)
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For flat universe !
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With free !
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For flat universe !
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The constraints on A and C related with the correlation: i.e., in the literature C is set to [0.89, 1.05]; A is set to 1.5 One can find that, this will lead to the bias to the final constraints on The cosmological parameters!
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0802.4262: By Nan Liang et al.
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Take into account the recent weak lensing data: 100 square degree from (the CFHTLS-Wide, RCS, VIRMOS-DESCART and GaBoDS surveys) H.Li et al., e-Print: arXiv:0812.1672
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Testing Oscillating Primordial Spectrum and Oscillating Dark Energy with Astronomical Observations J.Liu, H.Li, J.-Q. Xia & X.Zhang, e-Print: arXiv:0901.2033 This can be motivated by: Natural inflation, Planck scale physics and oscillating primordial spectrum X.L. Wang, et al. Int.J.Mod.Phys.D14:1347,2005
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The effects on the TT power spectrum and matter power spectrum
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SUMMARY The current status on determining the cosmological parameters with the data,paying particular attention to the Perturbation of DE; Cosmological constant fits the current data well We expect the Future observations like Planck and LAMOST will provide better constraints on the cosmological parameters ! H. Li, J.-Q. Xia, Zu-Hui Fan and X. Zhang, JCAP 10 (2008) 046
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