Abstract
One of the most fundamental properties of the Universe is its density, or more usefully the ratio Ω = ρ/ρc of the density to the critical value required for closure. The feeling among cosmologists is that the Universe is open, with Ω perhaps in the range 0.1–0.5 (see ref. 1). In general, Ω is thought of as a parameter to be deduced from observation, but some reasons for it having a particular value have been suggested; there is a certain aesthetic appeal in having Ω = 1 (ref. 2), and the ‘anthropic principle’3 suggests that Ω should not be too far from unity if the Universe is to evolve in such a way as to allow the development of stars, and thence ourselves. Here speculations are made concerning the transition from quantum to classical gravitational behaviour near the initial cosmic singularity, and a physical process is proposed whose action leads naturally to a Universe which is open.
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References
Gott, J. R. III, Gunn, J. E., Schramm, D. N. & Tinsley, B. M. Astrophys. J. 194, 543–554 (1974).
Dicke, R. H. & Peebles, P. J. E. in General Relativity: an Einstein Centenary Survey (eds Hawking S. W. & Israel, W.) 504–517 (Cambridge University Press, 1979).
Carter, B. in Confrontation of Cosmological Theories with Observational Data (ed. Longair, M. S.) 291–298 (Reidel, Dordrecht, 1974).
Carr, B. J. & Hawking, S. W. Mon. Not. R. astr. Soc. 168, 399–415 (1974).
Misner, C. W., Thorne, K. S. & Wheeler, J. A. Gravitation (Freeman, San Francisco, 1973).
Harrison, E. R. Phys. Rev. D1, 2726–2730 (1970).
Hawking, S. W. in General Relativity: an Einstein Centenary Survey (eds Hawking, S. W. & Israel, W.) 746–789 (Cambridge University Press, 1979).
Carr, B. J. Astrophys. J. 201, 1–19 (1975).
Gott, J. R. III A. Rev. Astr. Astrophys. 15, 235–266 (1977).
Guth, A. H. Phys. Rev. D23, 347–356 (1981).
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Lindley, D. Why is the Universe open?. Nature 291, 391–392 (1981). https://doi.org/10.1038/291391a0
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DOI: https://doi.org/10.1038/291391a0
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