Presentation is loading. Please wait.

Presentation is loading. Please wait.

Dark Matter, Dark Energy, and the Current State of Cosmology

Similar presentations

Presentation on theme: "Dark Matter, Dark Energy, and the Current State of Cosmology"— Presentation transcript:

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


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 SN

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?

Download ppt "Dark Matter, Dark Energy, and the Current State of Cosmology"

Similar presentations

Ads by Google