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What can we learn from CMB in the Planck area? (Planck is going to be launch May 6)

What can we learn from CMB in the Planck area? (Planck is going to be launch May 6)

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## What can we learn from CMB in the Planck area? (Planck is going to be launch May 6)

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**Whatcanwelearnfrom CMBin the Planck area?(Planck isgoing to**belaunch May 6) Yannick Giraud-Héraud (APC – Paris) • Thermal History of the Universe • and the standard Big-Bang model • The CMB • itsorigin • a tool for Cosmology • past and forthcoming observations LHC conference - Isfahan**The Big Bang Model**• General Relativity(Einstein 1915 ; Friedmann 1922 ; Lemaître 1927) dark energy curvature matter Expansion CMB BBN LHC conference - Isfahan April 21, 2009**Thermal History of the Universe and the CMB**1. inflation (1/2) GUT? • Briefperiod of exponential expansion • (factor 1026 in ~ 10-34 s) • 1) Resolveflatness, 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 favourtoday, 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 Universeis made of? For each component the densityisdefined in terms of the criticaldensity: 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 attdec ~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 atmatter-radiationequality • 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**SphericalHarmonics 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 powerspectrum • Angular power spectrum • ~number of fluctuations in respect to their size • Cℓ • ℓ isinverselyproportional to the angular size ℓ=200 corresponds to q~1o LHC conference - Isfahan**Thermal History of the Universe and the CMB**Linear polarisation is due to Thomson scattering (Rees, 1968). 8. CMB polarisation anisotropies The polarisation of the CMB shouldbesmall as itis Produced by temperature anisotropies LHC conference - Isfahan**Thermal History of the Universe and the CMB**Wayne Hu pure E pure B 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 LHC conference - Isfahan**Thermal History of the Universe and the CMB**8. CMB polarisation: power spectra -probe of the structure of the Universe - primordial gravitationalwaves: smoking gun probe of inflation LHC conference - Isfahan**Key dates of the CMB observations**LHC conference - Isfahan**CMB detectionhistory**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**CMB detectionhistory**pivot secondary horns bolometers cryostat primary Balloon experiments (2000-2002): Boomerang, Maxima, Archeops Archeops (2002) from COBE scale to first acousticpeak LHC conference - Isfahan**CMB detectionhistory**WMAP – NASA satellite (launch 2001) • 2 back to back telescopes • Radiometerscooled down at90 K • Bands at23, 33, 41, 61 et 94 GHz • Angularresolution13-52’ • Sensitive to polarisation • Rotation 7.57 mHz LHC conference - Isfahan**WMAP/ACBAR power spectrum**Cosmologicalparameters estimation (WMAP+Acbar+CBI+LargeScale 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: EuropeanCommunity (Germany, Denmark, Spain, Finland, France, Italy, Irland, Netherland, UK, Sweden), Canada, Norvege, Switzerland, USA LHC conference - Isfahan**Planck**launchscheduled May 6 Herschel LHC conference - Isfahan**Planck isgoing to orbitaround the 2ndLagrangian point of the**Sun-Earth-Moon system • the skywillbescanned in 6 months • the mission isexpected to last 30 months LHC conference - Isfahan**LowFrequencyInstrument (LFI)**• Frequencies: 30 - 70 GHz • Wavelengths: 1cm - 5 mm • radio detectors (22) • Temperature: 20 K (Front-end), 300 K (Back-end) • Angularresolution: 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 FrequencyInstrument (HFI)**• Frequencies: 100 - 860 GHz • Wavelenghts: 3mm à 400µm • Detectors: 52 bolometers • Temperature: 0.1 K • Angularresolution: 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**Bolometers “Spider web”(Caltech/JPL)**121 Bolometers on a Wafer NTD Germanium 857 GHz Bolometer LHC conference - Isfahan**Frequency Observations**• Large bandwithcoverage : 9 bands This willallow to subtractforegrounds to the CMB • Polarizationmeasurement LHC conference - Isfahan**High AngularResolution**(5’ for Planck and 7o for COBE) LHC conference - Isfahan**High precisiontemperaturemeasurement**Planck COBE Planck WMAP (8 ans) Planckwill have: ~ 20 x WMAP sensitivity ~ 3 xangularresolution LHC conference - Isfahan**Main Planck Scientific Goals**• for temperaturemeasurements:definitivemeasurements up to l=2000 • onlylimited by photon noise of the CMB (astrophysicalforegrounds • becomethe major source of uncertainty) • CMB polarizationmeasurementswillbe the challenging part of Planck • for E mode up to l=1000 • Impact on the knowledge of the Big Bang model and on • FundamentalPhysics • cosmologicalparametersat the % level • firstconstraints on inflation • Studyof the large scale structure willbeadressedthrough : • Sunyaev-Zeldovitchsurvey : 10000 clusters as good tracers of the • dynamics of the Universe • B polarizationmeasurement • study of the MilkyWay • limiton neutrino mass LHC conference - Isfahan**Planck simulatedmaps**LHC conference - Isfahan**Temperature Power Spectrum**• Power spectrummeasurement up the 8th acousticpeak • Just cosmic variance limited up to l ~2500 l l 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 spectrumwill help to reduce the degeneracy to determine the cosmologicalparameters LHC conference - Isfahan**CosmologicalParameters**• Improvment of the knowledge of the • cosmologicalparameters • Ex: Ωbprécision • 10 times better • thanwith WMAP. • Degeneracieswillbereduced (polarisation) • Ex: discrimination betweenadiabatic • and isocurvature perturbations WMAP Planck PLANCK LHC conference - Isfahan**DarkEnergy Equation of State**Darkenergy, responsable of the acceleration of the expansion of the Universe, hasan equation of state: p = w For a pure cosmological constant: w = -1 Planckwillcontribute to the measurement of w togetherwithother probes (SNIa, Large Scale Structure, BaryonicAcoustic Oscillation, weaklensing, …), LHC conference - Isfahan**Reionisation of the Universe**• After a periodwhere the Universewasneutral, a phase of reionisationoccuredwhen the first objects (stars?) have been created • Signatureat large angularscales: pic dans le spectre EE (WMAP) WMAP+ACBAR+LSS Optical depth = 0,091+-0.008 • Planckwillbe able to discrimatebetweendifferentmodels of the first object formation LHC conference - Isfahan**WMAP/Planck capacitymeasurement of ns**ns = 1 for the redsolid line LHC conference - Isfahan**WMAP/Planck capacitymeasurement of ns**ns = 0.95 and no running for the redsolid line LHC conference - Isfahan**Constraints on tensor modes with Planck**B polarizationmeasurementsatlow l will put constraints on r (Planck 24 monthsurvey) Efstathiou, Gratton astroph:0903.0345 simulationwith r=0.1 and t=0,17 simulationwith r=0.1 and t=0,17 r=0.05 couldbedetected by Planck andupperlimit r<0.03 (95% CL) couldbe set LHC conference - Isfahan**Non-gaussianityproperties of the anisotropies**• Inflation modelspredictnearlyperfect model dependantGaussian fluctuations • Detectionof non-gaussianitywillbe crucial to discriminatebetweenthesemodels • Methods: kurtosis, skewness, 3 point statistics, test of isotropy … WMAP data Very cold region LHC conference - Isfahan**Secondary anisotropies: gravitationallensing of the CMB**Duringtheir trip, CMB photons are gravitationalyslightlydeviated by structures of the Universe • Coherentdeviation of the polarisation at large scale: B mode polarisation atsmallscale (leakfrom E mode to B mode) Non-gaussian signatures shouldbedetected by Planck • Neutrino mass affects structure formation Upperlimit on mn: 0.15 eV LHC conference - Isfahan**And a lot of otherstudieswillbeperformed by**astrophysicists… Clusters of galaxies: 30 000 clusters willbedetected by Planck usingSunyaev-Zel’dovitcheffect (interaction of CMB photons with hot electron gaz in the core of the galaxy clusters) Extragalactic sources (first surveysince FIRAS 1992 withl>100mm) Study of the MilkyWay: dust, free-free, synchrotron radiation magneticfield LHC conference - Isfahan