Spacetime Foam and the Cosmological Constant
Abstract
In the saddle point approximation, the Euclidean path integral for quantum gravity closely resembles a thermodynamic partition function, with the cosmological constant Λ playing the role of temperature and the ``density of topologies'' acting as an effective density of states. For Λ<0, the density of topologies grows superexponentially, and the sum over topologies diverges. In thermodynamics, such a divergence can signal the existence of a maximum temperature. The same may be true in quantum gravity: the effective cosmological constant may be driven to zero by a rapid rise in the density of topologies.
- Publication:
-
Physical Review Letters
- Pub Date:
- November 1997
- DOI:
- 10.1103/PhysRevLett.79.4071
- arXiv:
- arXiv:gr-qc/9708026
- Bibcode:
- 1997PhRvL..79.4071C
- Keywords:
-
- General Relativity and Quantum Cosmology;
- High Energy Physics - Theory
- E-Print:
- 8 pages, LaTeX. Two minor revisions (scaling parameter corrected with new reference