Determination of cosmological parameters Gong-Bo Zhao, Jun-Qing Xia, Bo Feng, Hong Li Xinmin Zhang IHEP, Beijing

Beijing2nd Sino-French Workshop Universe encoded in Parameter space Dark energy perturbation ??

Beijing2nd Sino-French Workshop Dark energy perturbations when w crossing -1 Dark energy & Inflation Outline Global fitting results of dark energy parameters Dark energy & neutrino mass limit Bump-like dark energy 5 Searching for CPT violation 6

Beijing2nd Sino-French Workshop 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

Beijing2nd Sino-French Workshop

Beijing2nd Sino-French Workshop Feng, Wang & Zhang Astro-ph/ Huterer & Cooray Astro-ph/ z w

Beijing2nd Sino-French Workshop 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/ ) A new scenanio of Dark Energy : Quintom (Zhang et al. Astro-ph/ ) For ex: single scalar: multi-scalar:

Beijing2nd Sino-French Workshop Astro-ph/ , Steen Hannestad,Steen Hannestad Edvard Mortsell Adding CMB,LSS data

Beijing2nd Sino-French Workshop Include DE perturbation when parametrizing the EOS Seljak et al Astro-ph/ Ch. Yeche et al Astro-ph/ Neglect DE perturbations Including DE perturbation only when w>-1 BIASED!

Beijing2nd Sino-French Workshop Strategies to handle the fluctuation of Dark Energy Difficulty:

Beijing2nd Sino-French Workshop Perturbation of DE is continuous during crossing! Here δ and θ are the density perturbation and the divergence of the fluid velocity respectively Zhao et.al Phys.Rev.D 72, A way out based on quintom model

Beijing2nd Sino-French Workshop Our strategy to handle perturbations when w crosses -1 I. Quintessence – like perturbation II. Phantom – like perturbation III. Quintom-based perturbation

Beijing2nd Sino-French Workshop 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, , 2006

Beijing2nd Sino-French Workshop Jun-Qing Xia, Gongbo Zhao, Bo Feng, Hong Li and Xinmin Zhang Phys.Rev.D73, , 2006 WMAP+SDSS+Riess WMAP+SDSS+SNLS Comparision of global fitting results with SN Ia (Riess) and SNLS

Beijing2nd Sino-French Workshop Constrain on dark energy by WMAP (importance of perturbation) Relative error: ~9% Relative error > 50% !!

Beijing2nd Sino-French Workshop

Beijing2nd Sino-French Workshop Gong-Bo Zhao, Jun-Qing Xia, Bo Feng and Xinmin Zhang, astro-ph/

Beijing2nd Sino-French Workshop

Beijing2nd Sino-French Workshop

Beijing2nd Sino-French Workshop

Beijing2nd Sino-French Workshop 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 II.Interesting correlation between dynamical dark energy and neutrino mass

Beijing2nd Sino-French Workshop Dark energy & Inflation

Beijing2nd Sino-French Workshop WMAP3 + RIESS + SDSS (14 k-bands)

Beijing2nd Sino-French Workshop Neutrino mass limit and dynamics of dark energy Jun-Qing Xia, Gong-Bo Zhao, Bo Feng, Xinmin Zhang In preparation

Beijing2nd Sino-French Workshop

Beijing2nd Sino-French Workshop

Beijing2nd Sino-French Workshop

Beijing2nd Sino-French Workshop Bump-like dark energy

Beijing2nd Sino-French Workshop EoS with feature:

Beijing2nd Sino-French Workshop Probing this feature with GRB??

Beijing2nd Sino-French Workshop “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)

Beijing2nd Sino-French Workshop Precise Hubble diagram from SNe Ia From Dr. Xiao Feng Wang’s Hangzhou talk ( May, 2006)

Beijing2nd Sino-French Workshop Searching for CPT violation

Beijing2nd Sino-French Workshop predicting and Bo Feng, Mingzhe Li, Jun-Qing Xia, Xuelei Chen and Xinmin Zhang Phys. Rev. Lett. 96, (2006) (Note here the notation: G ~ E, C~ B)

Beijing2nd Sino-French Workshop Summary I. 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 II. Interesting correlation between ns, alphas & DE III. Interesting correlation between w1 neutrino mass IV. 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

Beijing2nd Sino-French Workshop