Please use this identifier to cite or link to this item: http://hdl.handle.net/2445/12309
Title: Noise induced transitions in semiclassical cosmology
Author: Calzetta, Esteban A., 1958-
Verdaguer Oms, Enric, 1950-
Keywords: Matèria interstel·lar
Relativitat (Física)
Gravitació (Física)
Teoria quàntica de camps
Espai i temps
Soroll
Interstellar medium
Relativity (Physics)
Gravitation
Quantum field theory
Space and time
Noise
Issue Date: 1999
Publisher: The American Physical Society
Abstract: A semiclassical cosmological model is considered which consists of a closed Friedmann-Robertson-Walker spacetime in the presence of a cosmological constant, which mimics the effect of an inflaton field, and a massless, non-conformally coupled quantum scalar field. We show that the back-reaction of the quantum field, which consists basically of a nonlocal term due to gravitational particle creation and a noise term induced by the quantum fluctuations of the field, are able to drive the cosmological scale factor over the barrier of the classical potential so that if the universe starts near a zero scale factor (initial singularity), it can make the transition to an exponentially expanding de Sitter phase. We compute the probability of this transition and it turns out to be comparable with the probability that the universe tunnels from ``nothing'' into an inflationary stage in quantum cosmology. This suggests that in the presence of matter fields the back-reaction on the spacetime should not be neglected in quantum cosmology.
Note: Reproducció digital del document publicat en format paper, proporcionada per PROLA i http://dx.doi.org/10.1103/PhysRevD.59.083513
It is part of: Physical Review D, 1999, vol. 59, núm. 8, p. 083513-1-083513-24
URI: http://hdl.handle.net/2445/12309
ISSN: 0556-2821
Appears in Collections:Articles publicats en revistes (Física de la Matèria Condensada)

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