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  • 1. “majority of its surface area is only about 10 feet above sea level” The Nobel Prize in Physics 2011 Bob Nichol (ICG Portsmouth)
  • 2. General Relativity Primer
  • 3. Cosmology Primer I  Assumptions   Cosmological Principle; not special place, time or physics   Homogeneous and isotropic; defines “simple” FRW metric  Assume GR and FRW metric; solve to get Friedmann’s equations (including Einstein’s Cosmological Constant) 2 2 ⎛ a ⎞ 8π ˙ k Λ H ≡ ⎜ ⎟ = ρ− 2 − ⎝ a ⎠ 3 R 3
  • 4. Cosmology Primer II Recession Velocity   Hubble discovered the expansion of the Universe in 1929  Einstein dropped his cosmological constant Distance from us   Next 70 years was the search for two numbers! $ 0 8 %G “Hubbles’ Constant” "0 # = 2 $0     Density of matter $ c 3H 0 Ω0 = 1 for a flat universe
  • 5. Distances and SNeIa Thermonuclear explosions of White Dwarf starsn White Dwarf accretes mass from or merges with a companion star, growing to a critical mass ~1.4Msun (Chandrasekhar) A violent explosion is triggered at or near the center, and the star is completely incinerated within seconds. In the core, light elements are burned in fusion reactions to produce ~0.6Msun Nickel. The radioactive decay of Nickel and Cobalt makes
  • 6. Standardizable CandlesA"er  correc(on,  σ~  0.16  mag   (~8%  distance  error)   Kim et al. 1997
  • 7. Industrial Astronomy Sciama Building Only ~1 SNe per ~100 years in our Galaxy
  • 8. SN Hubble Diagram (circa 1999) Ω = ΩM + ΩΛ W 0 € Ω0 = ΩM + ΩΛ Sciama Building € ICG only UK institute in SDSS-III a=1/(1+z)
  • 9. Nobel Prize 2011"for the discovery of the accelerating expansion of the Universe through observations of distant supernovae"
  • 10. Baryon Acoustic Oscillations  Initial fluctuation in DM. Sound wave driven out by intense pressure at 0.57c. Today. Baryons and DM in equilibrium. The final free stream, while baryons Photons configuration is the wave Initial fluctuation in DM. Sound original drivenat the center and anis at 0.57c. peak out still as pressure echo (the remain by intense pressure gone sound horizon) ~150Mpc in radius Illustrations by Martin White
  • 11. Standard Rulers in the Sky First year WMAP power spectrum 150Mpc WMAP 1st year data
  • 12. Flat Universe “Ruler” is 150Mpc and distance to CMB is known to high accuracy (z=1089) WMAP 1st year data
  • 13. TodayDensities known to ~10%
  • 14. Energy of Nothingness! Coincidence problem? pi w i (z) ≡ ρi € ρ DE ~ a−3(1+w ) Log[a0/a(t)] €
  • 15. Cosmological Constant −3(1+w ) ρ DE ~ a (10120 too small) €