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Cosmology and the origin of structure. Academic Training Lectures Rocky Kolb Fermilab, University of Chicago, & CERN. Rocky I : The universe observed Rocky II : The growth of cosmological structure Rocky III : Inflation and the origin of perturbations
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Cosmology and the origin of structure Academic Training Lectures Rocky Kolb Fermilab, University of Chicago, & CERN Rocky I: The universe observed Rocky II: The growth of cosmological structure Rocky III: Inflation and the origin of perturbations Rocky IV: Dark matter and dark energy
Rocky I: The universe observed • Cosmological parameters: • Power spectrum of large-scale structure: • Anisotropy of CMB:
Theoretical developments (1917-1927) • Cosmological principle • Robertson-Walker metric • Expansion natural
“… physically, he is a splendid specimen…” “… magnificent physique ….” “… manly …” “… loveable character …”
Observational developments (1912-1929) • Cosmological principle (extragalactic astronomy) • Universe expands
Riess et al astro-ph/9410054 Hubble’s data
Distance-luminosity relation light travels on geodesics
Distance-luminosity relation Example: matter + lambda • Program: • measure via • input and calculate
Type Ia supernova are standard candles Type Ia Supernovae Luminosity / Solar Luminosity -20 0 20 40 60 days
Type Ia supernova Hubble diagram apparent magnitude [log(distance)] Perlmutter et al. (1998) redshift z
cosmological constant, …some changing non-zero vacuum energy, … or some unknown systematic effect(s) WVACUUM maximum theoretical bliss WMATTER
Newton Einstein normal scale factor a time accelerated scale factor a vacuum energy? time
The accelerating universe? • Normal matter slows the expansion of the universe (deceleration). Gravity is attractive. • Negative pressure would push apart space. • “Vacuum energy” (the mass-energy density of • space) is positive, but its pressure is negative.
cosmological constant, …some changing non-zero vacuum energy, … or some unknown systematic effect(s) WVACUUM • The case for L: • acceleration 2) large-scale structure maximum theoretical bliss WMATTER
cosmological constant, …some changing non-zero vacuum energy, … or some unknown systematic effect(s) WVACUUM • The case for L: • acceleration • 2) large-scale structure 3) age of the universe maximum theoretical bliss WMATTER
t0 : age of the universe Chaboyer (2001) Cayrel (2001) First measurement of stellar uranium • white dwarf cooling • nucleocosmochronology • globular cluster evolution
cosmological constant, …some changing non-zero vacuum energy, … or some unknown systematic effect(s) WVACUUM • The case for L: • acceleration • 2) large-scale structure • 3) age of the universe maximum theoretical bliss • 4) flatness • W 0 = 1 • WM = 0.3 • 1 - 0.3 = 0.7 WMATTER
WB h2~ 0.02 QSO 1937-1009 Ly-a Tytler Tytler
WM ~ 0.3 galaxy kinematics • 0 = 1 WM = 0.3 • 1 - 0.3 = 0.7 x-ray gas lensing
Cosmo-illogical constant Mass density of space: Who ordered that? The unbearable lightness of nothing!
The cosmic food chain (Wi) Radiation: 0.02% Visible matter: 0.1% Neutrinos: 0.1% Dark neutrons & protons: 9.78% Dark matter: 30% Dark energy: 60%
Observer’s view of the universe NGC 6070 lumpy (inhomogeneous and anisotropic) full of stars, galaxies, clusters, ….
Theorist’s view of the universe Actual image of dark matter smooth (homogeneous and isotropic) full of dark matter (and dark energy)
Power spectrum • Assume there is an average density • Expand density contrast in Fourier modes • Autocorrelation function defines power spectrum
Power spectrum sphere of radius R • Power spectrum related to rms fluctuations
Observer’s view of the universe (fluctuations)
Theorist’s view of the universe (isotropic)
Angular power spectrum LAST CENTURY
Angular power spectrum MAP expected precision
Rocky I: The universe observed • Cosmological parameters: • Power spectrum of large-scale structure: • Anisotropy of CMB:
Cosmology and the origin of structure Academic Training Lectures Rocky Kolb Fermilab, University of Chicago, & CERN Rocky I: The observed universe Rocky II: The growth of cosmological structure Rocky III: Inflation and the origin of perturbations Rocky IV: Dark matter and dark energy