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Precision cosmology, status and perspectives

Precision cosmology, status and perspectives. GGI Conference on “ The Dark Matter connection: Theory & Experiment” Florence, May 17 th 2010. Alessandro Melchiorri Universita’ di Roma, “La Sapienza”

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Precision cosmology, status and perspectives

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  1. Precision cosmology, status and perspectives GGI Conference on “The Dark Matter connection: Theory & Experiment” Florence, May 17th 2010 Alessandro Melchiorri Universita’ di Roma, “La Sapienza” INFN, Roma-1

  2. The Cosmic Microwave Background Discovered By Penzias and Wilson in 1965. It is an image of the universe at the time of recombination (near baryon-photons decoupling), when the universe was just a few thousand years old (z~1000). The CMB frequency spectrum is a perfect blackbody at T=2.73 K: this is an outstanding confirmation of the hot big bang model.

  3. The Microwave Sky COBE Uniform... Dipole... Imprint left by primordial tiny density inhomogeneities (z~1000).. Galaxy (z=0)

  4. WMAP

  5. Larger scales

  6. CMB Anisotropies Visibility Function Gravity ISW Doppler Adiabatic Fourmechanisms are responsablefor CMB anisotropies: • Gravity (Sachs-Wolfe effect) • Intrinsic (Adiabatic) Fluctuations • Doppler effect • Time-Varying Potentials (Integrated Sachs-Wolfe Effect)

  7. Hu, Sugiyama, Silk, Nature 1997, astro-ph/9604166

  8. WMAP

  9. We can measure cosmological parameters with CMB ! Wtot , Wb , Wc, L, t, h, ns, … Temperature Angular spectrum varies with

  10. DATA How to get a bound on a cosmological parameter Fiducial cosmological model: (Ωbh2 , Ωmh2 , h , ns , τ, Σmν) PARAMETER ESTIMATES

  11. Dunkley et al., 2008

  12. New WMAP resultsfrom 7 yearsofobservations Komatsuet al, 2010, 1001.4538

  13. Improvement in constrainingInflationaryParametersfrom WMAP5 to WMAP7 Ruling out n=1 (HZ spectrum) wouldbe a great success forinflation (primordialpertubations are producedby a dynamicalmechanism).

  14. Caveat(example): Constraints on inflationaryparametersdepend on assumptionof Suddenreionization scenario. A more generalschemebased on principalcomponents (Mortonson and Hu, MH) can put n=1 back in agreement withobservations. Planckwillsettle the issue. (no tensor) WMAP7 +MH + Tensors Pandolfi, Cooray, Giusarma, Kolb, Melchiorri, Mena, Serra, 2010 Dark MatterAnnihilation -> extra photons -> differentionization scenario -> n=1 ok !

  15. Komatsuet al, 2010, 1001.4538

  16. Small scale CMB can probe Heliumabundance at recombination. Changes in the visibility function.

  17. Komatsuet al, 2010, 1001.4538

  18. CMB Anisotropies Visibility Function Gravity ISW Doppler Adiabatic Fourmechanisms are responsablefor CMB anisotropies: • Gravity (Sachs-Wolfe effect) • Intrinsic (Adiabatic) Fluctuations • Doppler effect • Time-Varying Potentials (Integrated Sachs-Wolfe Effect)

  19. Hu, Sugiyama, Silk, Nature 1997, astro-ph/9604166

  20. Komatsuet al, 2010, 1001.4538 Neutrino background. Changesearly ISW. Hintfor N>3 ?

  21. South Pole Telescope- SPT

  22. Atacama CosmologyTelescope ACT

  23. New small-scale CMB measurementsby ACT and SPT Flowleret al (ACT collaboration), 2010

  24. ThermalSunyaev-Zel’dovicheffect SPT samplingfrequencies at 150 and 220 GHz can discriminate itfromDusty Star FormingGalaxies (DSFG) foregrounds (ACT can’t).

  25. Unresolved Point Sources Thermal SZ Kinetic SZ M. Luekeret al (SPT collaboration), 2009

  26. SPT measuresan SZ amplitudelowerby a factor 2 thanexpected ! • Systematics ? • SZ model ? • New physics ? (Dark coupling, modified GR, Dark Matter) ?

  27. Planck Satellite launch 14/5/2009

  28. Planck First Light Survey (September 2009). Experiment is working as expected

  29. Blue: current data Red: Planck

  30. New Measurements, New Parameters ! • Neutrino masses • Neutrino effectivenumber • PrimordialHelium • FundamentalConstants

  31. Galli, Martinelli, Melchiorri, Pagano, Sherwin, Spergel, tobesubmitted 2010

  32. Galli, Martinelli, Melchiorri, Pagano, Sherwin, Spergel, tobesubmitted 2010

  33. Galli, Martinelli, Melchiorri, Pagano, Sherwin, Spergel, tobesubmitted 2010

  34. Galli, Martinelli, Melchiorri, Pagano, Sherwin, Spergel, tobesubmitted 2010

  35. CONCLUSIONS • Recent CMB measurementsfullyconfirmL-CDM. Improvedconstraints on inflation • IonizationHistorystilltobeprobedbyobservations. • Problemswithintegrated SZ effect on smallscales (nowtoo low). • With future measurementsconstraints on newparametersrelatedtolaboratory • Physicscouldbeachieved.

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