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Opening Thoughts

Opening Thoughts. COSMO-02. Wendy Freedman Carnegie Observatories, Pasadena CA Chicago, September 2002. Goals set by our friendly Organizing Committee…. Dear Wendy and David:

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Opening Thoughts

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  1. Opening Thoughts COSMO-02 Wendy Freedman Carnegie Observatories, Pasadena CA Chicago, September 2002

  2. Goals set by our friendly Organizing Committee… Dear Wendy and David: Cosmo-02 has proven even more popular than we had anticipated… Your two presentations constitute the opening and closing of the conference,… we are asking you for a combination of judgment, advice, inspiration and prognostication for its practictioners. And I’ll tell you what the dark energy is…

  3. Goals set by our friendly Organizing Committee… Dear Wendy and David: Cosmo-02 has proven even more popular than we had anticipated… Your two presentations constitute the opening and closing of the conference,… we are asking you for a combination of judgment, advice, inspiration and prognostication for its practictioners. (In particular we are *not* looking for an overview or summary – give us your personal point of view.) The talks are short (25 minutes…) and we realize that we are asking you to do the nearly impossible. We trust that all of our speakers will make an extra effort to come as close as possible to the unrealistic goals we have set for them. Sincerely,

  4. Successes: • Inflation, gravitational instability plus cold dark matter…

  5. Power Spectrum 2dFGRS G~ Wmh ~ 0.25 § 0.05 Tegmark (2002) Primordial power spectrum: P(k) / kn (n=1 scale invariant)

  6. CMB Anisotropies W0 = 1.03 § 0.03 T0 = 2.725§ 0.001K flat geometry Dasi, Boomerang, MAXIMA, CBI n = 1.05 § 0.06

  7. Troubles: Inflation + Cold Dark Matter • poor fit to galaxy power spectrum for Einstein-de Sitter model • (SCDM: Wm = 1, L = 0, h = 0.5) • 2.predicts excess of small satellites • 3. predicts central cusps in density profiles } on small scales 1. Power spectrum 2. Numbers of satellites 3. Cuspiness of profiles SCDM tCDM Moore et al. 1999 model Moore et al. Jenkins et al. (1997) data LCDM OCDM

  8. Neils Bohr “How wonderful that we have met with a paradox. Now we have some hope of making progress.” -Neils Bohr

  9. Taking Stock of Where We Are Einstein-de Sitter model fails because: • CDM simulations fail to fit distribution of galaxies on large scales • no evidence for Wm = 1 • age discrepancy X-ray gas Lensing Galaxy kinematics Cluster baryons Wm ~ 0.3 Open universe fails because: • CMB anisotropies yield W0 = 1 • Variants to CDM: • Hot dark matter fails because: • free streaming wipes out seeds for structure formation

  10. Taking Stock of Where We Are Lambda CDM universe current winner because: • excellent fit to galaxy power spectrum on large scales • consistent with faint supernovae at high redshifts • resolves age discrepancy • consistent with LSS+CMB anisotropy results • no single point failure … and no better alternatives!

  11. Inflation + Cold Dark Matter+ Dark Energy Wm = 0.3 WL= 0.7 h = 0.7 2Df Power Spectrum + L CDM Supernovae from Percival et al. 2001 CMB H0 Key Project

  12. Critical Missing Pieces to the Current “Standard Model” • Cold dark matter dominates the matter density and is in an unknown form • The overall mass-energy density is dominated by dark energy, for which there is currently no explanation • The dynamics of inflation depends on particle physics at high energy, and nothing is known of the hypothetical scalar field that drives inflation

  13. The Challenge: “The mystery of the cosmological constant is probably the most pressing obstacle to significantly improving the models of elementary particle physics derived from string theory.” Witten (2000) 1. Why the small value? Observed: r· 10-30 g cm-3 Quantum field theory: r = 1 Quantum gravity: r· 10+90 g cm-3 Supersymmetry: r· 10+30 g cm-3 2. Why now? Planck WL EW NOW BBN Carroll (2001) log(a)

  14. L : Blunder, Convenient, or Correct? SN1a CMB 1900 1920 1940 1960 1980 2000 Year Freedman (2000)

  15. Cosmological Framework W0´r / rcrit rcrit = 3H02/8pG r = rb + rCDM + rn + rrad + rX +… Essential to determine equation of state for dark energy:

  16. Cosmological Framework W0´r / rcrit rcrit = 3H02/8pG r = rb + rCDM + rn + rrad + rx +… Essential to determine equation of state for dark energy : w = P(z) / r(z) Matter: rm/ (1+z)3 w = 0 Radiation: rr/ (1+z)4 w = 1/3 Vacuum: rL/ (1+z)0 w = -1 r(z) / (1 + z)3(1+w)

  17. 16 Cosmological Parameters 2 sets of parameters: • first set: 10 parameters describing FLRW model • -- the expansion • -- global geometry • -- age • -- composition • H0, q0, w, t0, T0, W0, Wb, WCDM, Wn, Wx • second set: 6 parameters describing the • deviations from exact homogeneity • S, T, s8 , n, nT , dn/d ln k Freedman & Turner (Science, 2002)

  18. Table of Cosmological Parameters Part I: 9 global FLRW parameters: Freedman & Turner (Science, 2002)

  19. Table of Cosmological Parameters Part II: 6 fluctuation parameters: Freedman & Turner (Science, 2002)

  20. CMB Anisotropies • Robust measure of W0 • But large degeneracies • Can have same geometry, but very different matter content • To break degeneracies: H0, SNIa, galaxy power spectrum, weak lensing • CMB measurements give no information on w(z) Wm and WL are not measured independently from the CMB alone. H0=70 Lineweaver (2001)

  21. Angular power spectrum MAP expected precision

  22. Constraining Quintessence Solid line: wq = -0.8 Dashed line: w= -1 A Challenge!!! Best fit: wq = -0.8 Wq= 0.72 Baccigalupi et al. 2001

  23. Prognostication*** Einstein will turn out to be right about the cosmological constant *** Beware of observers willing to tell the future….

  24. Prognostication*** Einstein will turn out to be right about the cosmological constant Rmn –1/2Rgmn = 8pGTmn + Lgmn “My biggest blunder” Either way!… *** Beware of observers willing to tell the future….

  25. Fermilab Looking Ahead COBE SNAP CERN Predicted Planck Planck Cyclic Branes ??? CMB Polarization LHC prototype beam collider LISA orbit Direct expansion rate: 2 m/s/century! OWL – 100m telescope CDMS in the Soudan mine

  26. The Magellan Telescopes Magellans I and II domes Las Campanas, Chile Carnegie Harvard MIT Arizona Michigan

  27. Carnegie/Las Campanas Infrared SN Survey • Infrared Hubble diagram • Decline-rate relation • UBVRIJHKobservations • 3 telescopes, coordinated • followup, 5 years • H-band may • be insensitive • to decline rate >300 6.5m Magellan nights (2003-2008) Hamuy et al. (2001)

  28. Carnegie Centennial Symposium Carnegie Centennial Lectures Measuring and Modeling the Universe Malcolm Longair John Schwarz Lisa Randall Michael Turner Alan Guth Steven Weinberg Marc Kamionkowski Wendy Freedman John Carlstrom Chris Kochanek John Tonry Joe Silk David Spergel Andrew Lange Matias Zaldiarraga Tony Readhead Lyman Page Sandy Faber Roger Blandford Alex Filippenko November 18-22, 2002 Pasadena, CA http://www.ociw.edu/ociw/symposia/symposium2

  29. Are We Living in a Golden Age?

  30. Are We Living in a Golden Age? Or are we still living in a Bronze Age?…

  31. Are We Living in a Golden Age? Or are we still living in a Bronze Age?… Or taken to epicycles?…

  32. Are We Living in a Golden Age? Or are we still living in a Bronze Age?… Let us look forward to an Age of Reason and understanding!…

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