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More buzz words, etc. Structure evolution and types of WIMPS PowerPoint Presentation
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More buzz words, etc. Structure evolution and types of WIMPS

More buzz words, etc. Structure evolution and types of WIMPS

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More buzz words, etc. Structure evolution and types of WIMPS

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  1. More buzz words, etc. • Structure evolution and types of WIMPS • Bottom-up <=> Cold Dark Matter(CDM) • Top-Down <=> Hot Dark Matter (HDM) • “Cold” = “slow” = less then 1/10 speed of light • “Hot” = “fast” = 0.99 or closer to speed of light • Galaxies seen far away => formed early = bottom up = CDM

  2. Key points to derivation ofwe live in flat universe From CBM: We assume we know how to calculate the size of the brick wall fluctuations! [Remember we assume ADIABATIC fluctuations] Apparent size depends ENTIRELY on the curvature of the of the universe => we think we’re flat “for sure” But only if adiabatic fluctuations apply!

  3. Is there a way out? Yes! =“Isocurvature” fluctuations • Dissociate the matter from the light • “Brick wall” can be as smooth as you please • Apparent size of the brick wall fluctuations • Ambiguous => • Assume a size that agrees with any geometry • ( k = -1, 0 , 0r 1

  4. Summary: CMB associated with Big Bang BB plus GR says Universe was hot and is expanding CMB measurements with model fitting: Most likely universe is flat

  5. Summary cont.: If universe is flat, there is lots (90%-95%) of something that is not ordinary (baryonic) matter. But clusters say only 30% of W can come from all forms of matter. Therefore CMB + Clusters says need Dark Energy to make up the difference Agrees with SNe Ia

  6. CMB SNe Ia clusters

  7. Summary Cont. So Wm = 0.3, WL= 0.7, k = 0 (flat) will expand forever in an accelerating manner • Problem is “crazy” universe: • Dark Energy, non-baryonic matter, invisible baryonic matter. Ways out: • We’ve just screwed up big time • Isocurvature can remove dark energy (from k = 0 and matter limits) from CMB measurements BUT still have SN Ia! Time will tell

  8. Brick Building or Pack of Cards? Clusters say Wm 0.3 “Final” Answer: Wt = W_L +Wm = 1; k = 0; Wb = 0.05, WCDM = 0.25, WL = 0.7 Supernovae says dark energy CDM CMB “1st peak,” universe flat = Wtotal = 1, k = 0 Galaxies formed early Non-ordinary [but real] matter (non-baryonic), lots Big Bang Galaxies and Clusters exist GR + CMB total +expanding universe General Smoothness of CMB

  9. Onwardho! • OK, where do supernovae fit in and how? • First the concept: the standard candle • If know how bright something is intrinsically, then if you can measure it’s apparent brightness, you can calculate the Distance (D) • Apparent brightness = intrinsic brightness/4pD2 • For Euclidian spaceD is “normal”