Abstract: (arXiv)
The old cosmological constant problem is to understand why the vacuum energy is so small; the new problem is to understand why it is comparable to the present mass density. Several approaches to these problems are reviewed. Quintessence does not help with either; anthropic considerations offer a possibility of solving both. In theories with a scalar field that takes random initial values, the anthropic principle may apply to the cosmological constant, but probably to nothing else.
  • inspirereview:I-vg-1
  • talk: Marina del Rey 2000/02/23
  • cosmological constant
  • quintessence
  • energy: density
  • anthropic principle
  • cosmological model
  • field theory: scalar