Dark MatterEnergy

1
Dark Matter/Energy

• Kenneth Carrell

2
Why Dark Matter?

• Not enough mass in the universe.
• Data suggests that galaxies have more than just
  the luminous matter.
• Rotation curves
• Galaxy clusters

3
What is DM made of?

• MACHOs
• MAssive Compact Halo Objects
• WIMPs
• Weakly Interacting Massive Particles
• SUSY particles
• Neutrinos
• Other inos
• Axions, etc.

4
What are WIMPs?

• Remnants from the Big Bang.
• If neutrinos have mass, they account for part of
  the missing mass problem, but not all (m? 10
  eV).
• Heavy particles that rarely interact.

5
How to find WIMPs

• First you have to assume they will interact with
  normal matter.
• Popular form of searching
• Look for sinusoidal detection of particles due to
  the Earth moving through the sea of WIMP
  particles.
• You need large detectors that are extremely
  sensitive and have really low backgrounds.

6
DAMA Results
7
Current DM Experiments

• WIMPs
• CDMS (at Center for Particle Astrophysics,
  Berkeley)
• CRESST (Munich - Oxford - INFN)
• DAMA (Beijing - Rome - Frascati)
• EDELWEISS (France)
• ELEGANTS-V (Kamioka)
• GENIUS
• HDMS (Heidelberg Dark Matter Search)
• ORPHEUS
• PICASSO (Montréal)
• Saclay
• bb-decay experiments
• Heidelberg - Moscow
• Milan
• Neuchatel - Caltech - PSI
• USC - PNL - Zaragoza
• SUSY WIMP interactive limit plotter
• MACHOs
• France (AGAPE) and POINT-AGAPE Collaboration

8
CDMS
9
DAMA
10
Current Limits
11
Einstein's Theory of General Relativity
Rµ? (gµ?R)/2 8pGTµ?
Changed To
Rµ? (gµ?R)/2 ?gµ? 8pGTµ?
12
? was later abandoned because

• The entire universe was found to not just be the
  Milky Way galaxy.
• Hubble discovered that the universe was
  expanding.
• Einstein considered this one of his greatest
  mistakes.

13
Here is what astronomers generally believed to be
true of the universe in the late 1900s (lt1998)

• The universe was flat (O0 1, ? 0).
• The force of gravity was the dominant force at
  large distances.
• This would cause a deceleration in the expansion
  of the universe

14
(No Transcript)
15
(No Transcript)
16
Status

• The distances to the SNe are farther away than
  would be expected for OM 0.2, O? 0
• Explanation given by cosmological constant with gt
  99.7 confidence level (with OMgt0)
• The data is consistent with an accelerating
  expansion (q0 lt 0) with gt 99.5 confidence level.
• The universe will expand forever.
• The age of the universe 14.5 Gyr.

17
References

• http//cdms.berkeley.edu/
• http//www.lngs.infn.it/lngs/htexts/dama/
• http//dmtools.berkeley.edu/limitplots/
• http//www.physto.se/edsjo/darksusy/
• http//www.supernova.lbl.gov/