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History of the Universe. Inflation, the Problem Solver. A. Horizon Why is the CMB radiation so isotropic? Flat Universe Why is the density of the Universe so close to critical? Structure Where does structure come from? GUTs suggest that Universe did undergo inflation.
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Inflation, the Problem Solver A. Horizon Why is the CMB radiation so isotropic? Flat UniverseWhy is the density of the Universe so close to critical? Structure Where does structure come from? GUTs suggest that Universe did undergo inflation
Inflation, the Problem Solver Milky Way Solar System phase transition strong nuclear force separates extreme pressure overwhelms gravity Electroweak
Inflation Solves Horizon Problem A. Horizonwhy is the CMB radiation so isotropic? observe … temp is 2.725 K with variation of 1 part in 100,000 in BB … two points in opposite directions could look different Universe tiny in past
Inflation Solves Horizon Problem smaller than proton cannot observe A+B can observe A+B
Inflation Solves Flatness Problem B. Flatness why is the density of Universe so close to critical? observe … matter density is 27% critical in BB … no reason why density close to critical Universe HAS to look flat if you inflate fast
Inflation Solves Structure Problem C. Structure where does structure come from? observe … CMB not completely uniform observe … galaxies/clusters exist in BB … quantum ripples in early Universe much too small inflation superstretches ripples into macro sizes
Structure Simulated REQUIRES DARK MATTER 1.0 Byr 3.5 Byr 13.7 Byr
Dark Matter: Cluster Motions Virial Theorem: for stable, self-gravitating, spherical distribution of equal mass objects: KE = –1/2 PE KE per galaxy = 1/2 mgv2 KE of N galaxies = 1/2 Nmgv2 = 1/2 Mcv2 PE per galaxy = –1/2 Gmgmg/R PE of N galaxies = –1/2 GNmgNmg/R = –1/2 GMc2/R Assume random orbits (no preferred rotation): 1/2 Mcv2 = 1/4 GMc2/R Mc = 2 v2R/G yields “Virial Mass” (with lots of galaxies, can see how VM changes with radius)
Dark Matter: 3D Map HST/ACS images of 8X full moon ground-based opt/ir/rad + space-based XMM-Newton measure shapes of half million galaxies to reveal “weak lensing” conclude: dark matter clumps over time
? Future Universe