2003/08/08 by Massimo Giovannini
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #astro-ph #hep-ph #hep-th
paper · pdf · doi:10.1088/0264-9381/20/24/016
published as Class.Quant.Grav. 20 (2003) 5455-5473 · 29 pages in Latex style
arxiv created 2003/08/08 · openalex publication_date 2003/11/12 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
Quantum-mechanical initial conditions for the fluctuations of the geometry can be assigned in excess of a given physical wavelength. The two-point functions of the scalar and tensor modes of the geometry will then inherit corrections depending on which Hamiltonian is minimized at the initial stage of the evolution. The energy density of the background geometry is compared with the energy–momentum pseudo-tensor of the fluctuations averaged over the initial states, minimizing each different Hamiltonian. The minimization of adiabatic Hamiltonians leads to initial states whose back-reaction on the geometry is negligible. The minimization of non-adiabatic Hamiltonians, ultimately responsible for large corrections in the two-point functions, is associated with initial states whose energetic content is of the same order as the energy density of the background.