We employ the semiclassical approximation to the Wheeler–DeWitt equation in the spatially flat de Sitter Universe to investigate the dynamics of a minimally coupled scalar field near the Planck scale. We find that, contrary to naive intuition, the effects of quantum gravitational fluctuations become negligible and the scalar field states asymptotically approach plane waves at very early times. These states can then be used as initial conditions for the quantum states of matter to show that each mode essentially originated in the minimum energy vacuum. Although the full quantum dynamics cannot be obtained exactly for the case at hand, our results can be considered as supporting the general idea of asymptotic safety in quantum gravity.
C. Appignani, R. Casadio (2008). Hints of (trans-Planckian) asymptotic freedom in semiclassical cosmology. JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS, 06, 014-014 [10.1088/1475-7516/2008/06/014].
Hints of (trans-Planckian) asymptotic freedom in semiclassical cosmology
CASADIO, ROBERTO
2008
Abstract
We employ the semiclassical approximation to the Wheeler–DeWitt equation in the spatially flat de Sitter Universe to investigate the dynamics of a minimally coupled scalar field near the Planck scale. We find that, contrary to naive intuition, the effects of quantum gravitational fluctuations become negligible and the scalar field states asymptotically approach plane waves at very early times. These states can then be used as initial conditions for the quantum states of matter to show that each mode essentially originated in the minimum energy vacuum. Although the full quantum dynamics cannot be obtained exactly for the case at hand, our results can be considered as supporting the general idea of asymptotic safety in quantum gravity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.