Dynamic vacuum variable and equilibrium approach in cosmology
- Institute for Theoretical Physics, University of Karlsruhe (Thailand), 76128 Karlsruhe (Germany)
A modified-gravity theory is considered with a four-form field strength F, a variable gravitational coupling parameter G(F), and a standard matter action. This theory provides a concrete realization of the general vacuum variable q as the four-form amplitude F and allows for a study of its dynamics. The theory gives a flat Friedmann-Robertson-Walker universe with rapid oscillations of the effective vacuum energy density (cosmological ''constant''), whose amplitude drops to zero asymptotically. Extrapolating to the present age of the Universe, the order of magnitude of the average vacuum energy density agrees with the observed near-critical vacuum energy density of the present universe. It may even be that this type of oscillating vacuum energy density constitutes a significant part of the so-called cold dark matter in the standard Friedmann-Robertson-Walker framework.
- OSTI ID:
- 21250836
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 78, Issue 6; Other Information: DOI: 10.1103/PhysRevD.78.063528; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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