1. Dark Matter, Dark Energy, and the Current State of Cosmology
Nick Kaiser
Institute for Astronomy
University of Hawaii

2. Fritz Zwicky

3. The Coma Cluster

4. Zwicky & the Missing Mass
Measured galaxy speeds in Coma
Virial theorem: M/L ~ 500 M_sun/L_sun
The “missing mass”
An outstanding problem in cosmology
90-98% of the universe is in a mysterious form
detectable only by its gravitational attraction

5. The Dark Matter Puzzle
Where is it?
How much is there?
What is it?

6. Cosmology in a nutshell:
The old cosmology
Friedmann; Einstein; de Sitter ….
The New Cosmology
Inflation - scalar fields
The Hot Big Bang
Structure Formation

7. The Friedmann Model Scale factor R(t)
mass density and curvature of space
problems
horizon
flatness

8. Inflationary Cosmology
In the beginning there was the field….
Vector, tensor and scalar fields
Weinberg-Salaam:
unified theory - the Higgs field
The “inflaton”
central to inflation
solves the old problems
predicts a flat universe =1
quantum fluctuations  structure formation

9. The Hot Big Bang The cosmic kitchen Abundance of “baryons” Relics
big bang nucleosynthesis
Abundance of “baryons”
baryons ~ 0.02
Relics
cosmic background
neutrinos

10. Structure Formation Quantum fluctuations gravitational instability
dark matter
the “cosmic web”

11. The Cosmic Web

12. The history of the Universe

13. Inventory of Dark Matter
Galaxies
luminous parts  M/L ~ 1-5
flat rotation curves  M/L ~ 30
Pairs … Groups … Clusters
M/L ~
Super-Cluster Dynamics
  = 1?

14. Galaxies

15. Gravitational Lensing
Gravity bends light rays
probe of dark matter
highly versatile
microlensing - “machos”
galaxy lensing
lensing by cluster
lensing by superclusters

16. Theory of gravitational lensing

17. Lensing by galaxies

18. Lensing by clusters

21. MACSJ2243

22. Cosmic Microwave Background
Relic from the big bang
Probe of t ~ 100,000 yr
COBE
large angle
BOOMERANG
small angles
flat Universe

23. COBE Satellite

24. The COBE Sky

25. From COBE to BOOMERANG

26. The Universe is flat!

27. What is the Matter? Neutrinos? Axions or other fields? WIMPs?
No longer popular
Axions or other fields?
WIMPs?
Etc etc etc….
Plenty of theory - scarce observations

28. Dark Energy Consensus model:  ~ 0.3 CMB   = 1
resolution: the accelerating Universe
expansion history from supernovae
fainter than expected
universe is being accelerated - dark energy
“late time inflation” - yet another field?

29. The Nearest Galaxies
LMC
February 22, 1987
SMC

30. Expansion History from SN9

31. The Current Status of Cosmology
A “working model” for creation of the Universe and the structure therein
Impressive concordance with current observations
Embarrassing number of ingredients
luminous baryons; dark baryons; neutrinos; dark matter; dark energy….
Epicycles?