• 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

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!

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

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

Summary cont.:If universe is flat, there is lots (90%-95%) of something that is not ordinary (baryonic) matter.

Therefore CMB + Clusters says need Dark Energy to make up the difference

But clusters say only 30% of can come from all forms of matter.

Agrees with SNe Ia

SNe Ia CMB

clusters

Summary Cont.So m = 0.3, = 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!

rick Building or Pack of Cards?

GR + CMB total +expanding universe

ig Bang

General Smoothness of CMB

Galaxies and Clusters exist

Non-ordinary [but real] matter (non-baryonic), lots

CMB “1st peak,” universe flat = total = 1, k = 0

Supernovae says dark energy

Galaxies formed early

CDM

Clusters say m 0.3

“Final” Answer: t = +m = 1; k = 0; b = 0.05, CDM = 0.25, = 0.7

Onward ho!

• 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 space D is “normal”