LHC conference - Isfahan What can we learn from CMB in the Planck area? (Planck is going to be launch May 6) Yannick Giraud-Héraud (APC – Paris) Thermal History of the Universe and the standard Big-Bang model The CMB its origin a tool for Cosmology past and forthcoming observations LHC conference - Isfahan
LHC conference - Isfahan The Big Bang Model General Relativity (Einstein 1915 ; Friedmann 1922 ; Lemaître 1927) matter dark energy curvature Expansion CMB BBN LHC conference - Isfahan April 21, 2009
Thermal History of the Universe and the CMB 1. inflation (1/2) GUT? Brief period of exponential expansion (factor 1026 in ~ 10-34 s) 1) Resolve flatness, horizon, relic … problems 2) Perturbation generation density (scalar) dm ~ EI6/V’ ~ 10-5 gravitational (tensor) dog ~ (EI/MPlanck)4 LHC conference - Isfahan
Thermal History of the Universe and the CMB 1. inflation (2/2) Slow roll potential, in favour today, are caracterized by 2 parameters They are related to spectral index of the density fluctuations V1/4~3.3x1016r1/4 GeV LHC conference - Isfahan
Thermal History of the Universe and the CMB 2. nucleosynthethis 3. thermalization LHC conference - Isfahan
Thermal History of the Universe and the CMB 4. temperature anisotropies theory 2dF LHC conference - Isfahan Large-scale structure
Thermal History of the Universe and the CMB 5. Energy Contents of the Universe What the Universe is made of? For each component the density is defined in terms of the critical density: Wcomposante = rcomposante/ rcritical rcritical ~ 5. GeV/m3 LHC conference - Isfahan
Thermal History of the Universe and the CMB 6. Geometry of the Universe Size of the horizon at tdec ~100 Mpc flat closed open LHC conference - Isfahan closed flat open
Thermal History of the Universe and the CMB 7. Shape of the Power Spectrum (1/3) Primordial Universe is dominated by radiation no matter collapse Baryon starts to collapse at matter-radiation equality Acoustic waves induced by radiation pressure propagate at the speed of sound Oscillations are frozen at the moment of decoupling LHC conference - Isfahan
Thermal History of the Universe and the CMB Spherical Harmonics Expansion (equivalent to Fourier transform) l 1/q : l=200 q=1 deg. 7. Shape of the Power Spectrum (2/3) = 0,9 ; m = 0,15 = 1 ; m = 0,25 = 1,1 ; m = 0,35 Statistically isotropic sky l(l+1)/(2TCMB2)Cl Angular power spectrum l LHC conference - Isfahan
Thermal History of the Universe and the CMB 7. Shape of the Power Spectrum (3/3) maps power spectrum Angular power spectrum ~number of fluctuations in respect to their size Cℓ ℓ is inversely proportional to the angular size ℓ=200 corresponds to q~1o LHC conference - Isfahan
Thermal History of the Universe and the CMB 8. CMB polarisation anisotropies Linear polarisation is due to Thomson scattering (Rees, 1968). The polarisation of the CMB should be small as it is Produced by temperature anisotropies LHC conference - Isfahan
Thermal History of the Universe and the CMB 8. CMB polarisation: decomposition in 2 modes E and B E modes – even parity : B modes – odd parity : - E modes are produced by quadrupolar sources (density fluctuations and gravitational waves) B modes are produced by gravitational waves and lensing of E modes pure E pure B Wayne Hu LHC conference - Isfahan
Thermal History of the Universe and the CMB 8. CMB polarisation: power spectra - probe of the structure of the Universe - primordial gravitational waves: smoking gun probe of inflation LHC conference - Isfahan
Key dates of the CMB observations LHC conference - Isfahan
LHC conference - Isfahan CMB detection history highly uniform discovered at 7.35 cm (4 GHz) (Penzias & Wilson, 1964) 2) dipole DT= 3 mK (Smoot et al. 1976) (Mather et al. 1999 - COBE) 3) Perfect black body (COBE Mather et al., 1999) 4) Anisotropies at 7o (COBE Smoot et al. 1992) LHC conference - Isfahan
LHC conference - Isfahan CMB detection history Balloon experiments (2000-2002): Boomerang, Maxima, Archeops primary secondary pivot horns bolometers cryostat Archeops (2002) from COBE scale to first acoustic peak LHC conference - Isfahan
CMB detection history WMAP – NASA satellite (launch 2001) 2 back to back telescopes Radiometers cooled down at 90 K Bands at 23, 33, 41, 61 et 94 GHz Angular resolution 13-52’ Sensitive to polarisation Rotation 7.57 mHz LHC conference - Isfahan
WMAP/ACBAR power spectrum Cosmological parameters estimation (WMAP+Acbar+CBI+Large Scale Structure Observations) ns = 0.948+-0.25 R<0.2 t = 0.091+-0.009 LHC conference - Isfahan
Planck: an ESA satellite CMB anisotropies measurements (temperature and polarization) International collaboration: European Community (Germany, Denmark, Spain, Finland, France, Italy, Irland, Netherland, UK, Sweden), Canada, Norvege, Switzerland, USA LHC conference - Isfahan
LHC conference - Isfahan Planck launch scheduled May 6 Herschel LHC conference - Isfahan
LHC conference - Isfahan Planck is going to orbit around the 2nd Lagrangian point of the Sun-Earth-Moon system the sky will be scanned in 6 months the mission is expected to last 30 months LHC conference - Isfahan
Low Frequency Instrument (LFI) Frequencies: 30 - 70 GHz Wavelengths: 1cm - 5 mm radio detectors (22) Temperature: 20 K (Front-end), 300 K (Back-end) Angular resolution: 12' (70 GHz) à 33' (30 GHz) Sensitivity @30 GHz: ~5.4 mK; @70 GHz: 12.7 mK PI: N. Mandolesi (CNR – Bologna/Italy) IS: M. Bersanelli (U. Milano/Italy) LHC conference - Isfahan
High Frequency Instrument (HFI) Frequencies: 100 - 860 GHz Wavelenghts: 3mm à 400µm Detectors: 52 bolometers Temperature: 0.1 K Angular resolution: 5' (850 GHz) à 9.2' (100 GHz) Sensitivity @100 GHz: ~ 5mK PI: J.L. Puget (IAS - Orsay) IS: J.M. Lamarre (LERMA – Paris) LHC conference - Isfahan
Thermal Architecture of Planck HFI Bolomètres 4K 1.6K 18K 0.1K LHC conference - Isfahan
LHC conference - Isfahan Bolometers “Spider web”(Caltech/JPL) 121 Bolometers on a Wafer NTD Germanium 857 GHz Bolometer LHC conference - Isfahan
Frequency Observations Large bandwith coverage : 9 bands This will allow to subtract foregrounds to the CMB Polarization measurement LHC conference - Isfahan
High Angular Resolution (5’ for Planck and 7o for COBE) LHC conference - Isfahan
High precision temperature measurement COBE Planck WMAP (8 ans) Planck Planck will have: ~ 20 x WMAP sensitivity ~ 3 x angular resolution LHC conference - Isfahan
Main Planck Scientific Goals for temperature measurements : definitive measurements up to l=2000 only limited by photon noise of the CMB (astrophysical foregrounds become the major source of uncertainty) CMB polarization measurements will be the challenging part of Planck for E mode up to l=1000 Impact on the knowledge of the Big Bang model and on Fundamental Physics cosmological parameters at the % level first constraints on inflation Study of the large scale structure will be adressed through : Sunyaev-Zeldovitch survey : 10000 clusters as good tracers of the dynamics of the Universe B polarization measurement study of the Milky Way limit on neutrino mass LHC conference - Isfahan
LHC conference - Isfahan Planck simulated maps LHC conference - Isfahan
Temperature Power Spectrum l l Power spectrum measurement up the 8th acoustic peak Just cosmic variance limited up to l ~2500 LHC conference - Isfahan
Polarisation Power Spectra Cross-spectrum TE (t=0.17) LHC conference - Isfahan
Polarisation Power Spectra EE spectrum (t=0.17) Adding EE power spectrum to TT power spectrum will help to reduce the degeneracy to determine the cosmological parameters LHC conference - Isfahan
Cosmological Parameters Improvment of the knowledge of the cosmological parameters Ex: Ωb précision 10 times better than with WMAP. Degeneracies will be reduced (polarisation) Ex: discrimination between adiabatic and isocurvature perturbations WMAP Planck PLANCK LHC conference - Isfahan
Dark Energy Equation of State Dark energy, responsable of the acceleration of the expansion of the Universe, has an equation of state: p = w For a pure cosmological constant: w = -1 Planck will contribute to the measurement of w together with other probes (SNIa, Large Scale Structure, Baryonic Acoustic Oscillation, weak lensing, …), LHC conference - Isfahan
Reionisation of the Universe After a period where the Universe was neutral, a phase of reionisation occured when the first objects (stars?) have been created Signature at large angular scales: pic dans le spectre EE (WMAP) WMAP+ACBAR+LSS Optical depth = 0,091+-0.008 Planck will be able to discrimate between different models of the first object formation LHC conference - Isfahan
WMAP/Planck capacity measurement of ns ns = 1 for the red solid line LHC conference - Isfahan
WMAP/Planck capacity measurement of ns ns = 0.95 and no running for the red solid line LHC conference - Isfahan
Constraints on tensor modes with Planck B polarization measurements at low l will put constraints on r (Planck 24 month survey) Efstathiou, Gratton astroph:0903.0345 simulation with r=0.1 and t=0,17 simulation with r=0.1 and t=0,17 r=0.05 could be detected by Planck and upper limit r<0.03 (95% CL) could be set LHC conference - Isfahan
Non-gaussianity properties of the anisotropies Inflation models predict nearly perfect model dependant Gaussian fluctuations Detection of non-gaussianity will be crucial to discriminate between these models Methods: kurtosis, skewness, 3 point statistics, test of isotropy … WMAP data Very cold region LHC conference - Isfahan
Secondary anisotropies: gravitational lensing of the CMB During their trip, CMB photons are gravitationaly slightly deviated by structures of the Universe Coherent deviation of the polarisation at large scale: B mode polarisation at small scale (leak from E mode to B mode) Non-gaussian signatures should be detected by Planck Neutrino mass affects structure formation Upper limit on mn: 0.15 eV LHC conference - Isfahan
And a lot of other studies will be performed by astrophysicists … Clusters of galaxies: 30 000 clusters will be detected by Planck using Sunyaev-Zel’dovitch effect (interaction of CMB photons with hot electron gaz in the core of the galaxy clusters) Extragalactic sources (first survey since FIRAS 1992 with l>100mm) Study of the Milky Way: dust, free-free, synchrotron radiation magnetic field LHC conference - Isfahan