Speaker
Описание
Abstract
An approximate solution to the semiclassical Einstein equation is obtained in two-mode
squeezed vacuum (TMSV (|ξ 2 >)) state formalism perturbatively and is found to obey the same
power-law expansion as that of classical Einstein equation. However, the semiclassical gravity
shows a significant difference that the Hubble constant does not oscillate, in contrast with the
oscillatory behavior observed in classical gravity, for a specific choice of squeezing angle. This
coherently oscillating scalar field in the TMSV state suffers from the phenomenon of
nonclassical particle creation due to the quantum fluctuation of the scalar field in the
expanding background cosmology. We also analyzed the validity of the semiclassical theory in
TMSV state and finally examined the nonclassicality of the above state in the oscillatory phase
of a massive scalar field.
Keywords: Scalar Field, Two-mode Squeezed Vacuum State, FRW Universe, Semiclassical
Approximation to gravity, quantum fluctuation, particle creation.
