180 likes | 194 Views
AST-IHEP-CPPM-DarkEnergy: Determination of cosmological parameters.
E N D
AST-IHEP-CPPM-DarkEnergy:Determination of cosmological parameters 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 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
Some words about cosmology Cosmology based on: Homogenous and isotropic Universe General relativity: G = 8GT 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) T = m + r + X (rc=10-29 g/cm3)
For a flat Universe: Z 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. Dark energy or cosmological constant caracterized by reduce density: W =r/rc Definition:W=r/rc(rc=10-29 g/cm3)
From observations to the Concordance Model SNe Ia CMB(WMAP) Universe is mainly dark LSS ~70% DE and ~25% DM. a 2006 status Definition:W=r/rc (rc=10-29 g/cm3)
What is this Dark Energy? Characterized by its equation of state w=p/ = w0+waz/(1+z) • Modified Gravity/GR ? • Non minimal Couplings? • Extra-Dimensions? • Anisotropy/ inhomogeneity effects? • Negative energy? New form of « field/matter? » Quintessence? Unified Dark Matter? Cosmological Constant???
How to extract w0,wa? Degeneracies between parameters imply multi-probes analysis sensitive to complementary quantities: Luminosity distance, angular distance, growth factor… Snapshot at ~400,000 yr, viewed from z=0 CMB Angular diameter distance to z~1000 Growth rate of structure (from ISW) Supernovae Standard candle Luminosity distance Cosmic Shear Evolution of dark matter perturbations Angular diameter distance Growth rate of structure Evolution of dark matter perturbations Cluster counts Angular diameter distance Growth rate of structure Baryon Wiggles Angular diameter distance
Important number of parameters (cosmological/astrophysical) • b/m density for baryon/matter • / nr density for neutrino’s • kcurvature density • h Hubble constant, • nsspectral index, • reionisation optical depth • A(~82) normalization for CMB, WL and BAO. • ms0 normalization for SNIa. • yhe Helium fraction • w0,wa 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/050717 Bayesian IHEP Astro-ph/060362
Dynamics of dark energy and curvature of universe WMAP3astro-ph/061272: IHEP/PKU/BNU/CPPM/CPT
ESR+EUchina VO Data Data CDM CDM Diane Talon-Esmieu 10000 hours of CPU Cosmological constraint using BAO • 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 VO Riess 2006 40000 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 THEGALAXY CLUSTER CL 0024+17 (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)}