Cosmological measures without volume weighting
- Theoretical Physics Institute, Department of Physics, University of Alberta, Room 238 CEB, 11322-89 Avenue, Edmonton, AB T6G 2G7 (Canada)
Many cosmologists (myself included) have advocated volume weighting for the cosmological measure problem, weighting spatial hypersurfaces by their volume. However, this often leads to the Boltzmann brain problem, that almost all observations would be by momentary Boltzmann brains that arise very briefly as quantum fluctuations in the late universe when it has expanded to a huge size, so that our observations (too ordered for Boltzmann brains) would be highly atypical and unlikely. Here it is suggested that volume weighting may be a mistake. Volume averaging is advocated as an alternative. One consequence may be a loss of the argument that eternal inflation gives a nonzero probability that our universe now has infinite volume.
- OSTI ID:
- 22156783
- Journal Information:
- Journal of Cosmology and Astroparticle Physics, Vol. 2008, Issue 10; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1475-7516
- Country of Publication:
- United States
- Language:
- English
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