AST-IHEP-CPPM-DarkEnergy: Determination of cosmological parameters Scientific Goal: Adress open questions of fundamental cosmology: dark matter/dark energy sector and primordial universe Few words about dark energy How to characterize dark energy Results already obtained by the Chinese and French groups Prospective Main people involved: Charling TAO, ZHANG XinMin, André TILQUIN, ZHAO Gongbo, QIAN Zuxuan, XIA Junqing, Diane TALON, FAN Zuhui, SUN Lei, Jean Marc VIREY, LI Hong, Zhu Zhonghong, Christian MARINONI, QIN Bo. Stefan Linden, DENG Jinsong, CHAO Wu, ZHOU Xu, WANG Xiaofeng CPPM/CPT/IHEP/PKU/NAOC/Tsinghua U/Beijing Normal U. + collaborators

Some words about cosmology Cosmology based on: Homogenous and isotropic Universe General relativity: G  = 8  GT  Energy content:  =  /  c Equation of state: w(z)=p/  Matter (  m ) : w =0 Radiation (  r ) : w = 1/3 Cosmological cste (   ): w=-1 Dark energy (  X ) : w(z) (  c = g/cm 3 )  T =  m +  r +  X

Some words about dark energy In 1998, the Supernova Cosmology Project and High-z team shown that high red-shift supernovae are fainter than expected: a new energy component is needed. Definition:  c (  c = g/cm 3 ) Z Dark energy or cosmological constant caracterized by reduce density:      c For a flat Universe:

From observations to the Concordance Model CMB(WMAP) SNe Ia LSS Universe is mainly dark ~70% DE and ~25% DM. a 2006 status Definition:  c (  c = g/cm 3 )

What is this Dark Energy? Cosmological Constant??? New form of « field/matter? » Quintessence? Unified Dark Matter? Modified Gravity/GR ? - Non minimal Couplings? - Extra-Dimensions? - Anisotropy/ inhomogeneity effects? - Negative energy? Characterized by its equation of state w=p/  = w 0 +w a z/(1+z)

How to extract w 0,w a ? Cluster counts Supernovae Baryon Wiggles Cosmic Shear Angular diameter distance Growth rate of structure Evolution of dark matter perturbations Angular diameter distance Standard candle Luminosity distance Evolution of dark matter perturbations Angular diameter distance Growth rate of structure CMB Snapshot at ~400,000 yr, viewed from z=0 Angular diameter distance to z~1000 Growth rate of structure (from ISW) Degeneracies between parameters imply multi-probes analysis sensitive to complementary quantities: Luminosity distance, angular distance, growth factor…

Important number of parameters (cosmological/astrophysical)  b /  m density for baryon/matter  /  nr density for neutrino’s  k curvature density h Hubble constant, n s spectral index,  reionisation optical depth A(~  8 2 ) normalization for CMB, WL and BAO. m s0 normalization for SNIa. yhe Helium fraction w 0,w a Equation of state…. Efficient statistical tools needed: Bayesian statistic and MCMC : Chinese and astrophysicist choice Frequentist statistic and datagrid : French and particle physicist choice Both groups made similar studies.

Dark energy with or without perturbations Frequentist CPPM/CPT Saclay Astro-ph/ Bayesian IHEP Astro-ph/060362

Dynamics of dark energy and curvature of universe WMAP3 astro-ph/061272: IHEP/PKU/BNU/CPPM/CPT

Cosmological constraint using BAO Data  CDM Results obtain during my 3 months stay to Beida University ESR+Euchina virtual organization and ZEN program (CPPM) BAO from BAOfit (Sun Lei from PKU. Join PhD) ESR VOESR+EUchina VO Riess hours of CPU Data  CDM Diane Talon-Esmieu hours of CPU

Data grid progress Installation of a Resource-broker, a SE at IHEP for the ESR (Earth Science Research) virtual organization. 4 machines at IHEP run our application. Members of Euchina VO Open CPPM machines to the Euchina virtual organization

Future program Phenomenological/theoretical aspects Use new probes, WL,SDSS… Use new theories (MG) or new classes of dark energy models Experimental aspects Systematical error studies and bias, i.e catastrophic redshift,SN evolution.. Wait for new data, I.e SNLS 3 years Technical aspect: Implement MCMC on datagrid Reinforce collaboration on European (ESR..) and EUchina datagrid Human aspect: Need other long term missions Need students

Technical progress (Datagrid). Our main goal was to re-enforce the connexion between Europe and China

Technical progress (2) Installation of a User Interface (UI) at Beida with 2 Graphical Interfaces Prepare and send jobs in the euchina grid Control the jobs and get job output

Technical progress (3) Installation of a Resource-broker (jobs driver) and a Storage- element at IHEP for the ESR virtual organization. European program from ESR can run on Chinese machines Opening of 4 machines at IHEP to run ESR applications (thanks to Zuxuan for negotiations). Our ZEN program runs on these machines. You want to make virtual travels ? Go to virtual organization on datagrid

Technical progress (4) Installation of the ZEN program on the euchina grid (we are now members) Opening of Marseille machines to the euchina virtual organization Chinese programs can run at Marseille (and also in Europe).

Other scientific results GALAXY DISTRIBUTION AS A PROBE OF THE RINGLIKE DARK MATTER STRUCTURE IN THE GALAXY CLUSTER CL (Pr. Bo Qin, Huan-Yuan Shan) The ring dark matter structure observed with lensing, is unlikely confirmed by galaxies distribution. Paper in preparation but still some work to simulate completeness of the galaxies survey from CFHT/WHT ( A&A 372, 391{405 (2001)}

Simulation