How Massive is the Universe?

• Describe with a cosmological mass density called _

• _ <1: Universe ‘open’: expands forever

• _ >1: Universe ‘closed’: Big Crunch

• _ =1: Universe ‘flat’

• Big Bang inflationary theory requires _total = 1 exactly

• Two types of matter

  • baryonic (p, n, etc.)
  • non-baryonic (_, WIMP, etc.)

Previous slide

Next slide

Back to first slide

View graphic version