Adiabatic regularization of the graviton stress-energy tensor in de Sitter space-time
Abstract
We study the renormalized energy-momentum tensor of gravitons in a de Sitter space-time. After canonically quantizing only the physical degrees of freedom, we adopt the standard adiabatic subtraction used for massless minimally coupled scalar fields as a regularization procedure and find that the energy density of gravitons in the E(3) invariant vacuum is proportional to H^4, where H is the Hubble parameter, but with a positive sign. According to this result the scalar expansion rate, which is gauge invariant in de Sitter space-time, is increased by the fluctuations. This implies that gravitons may then add to conformally coupled matter in driving the Starobinsky model of inflation.
Keywords
Cite
@article{arxiv.gr-qc/0407101,
title = {Adiabatic regularization of the graviton stress-energy tensor in de Sitter space-time},
author = {F. Finelli and G. Marozzi and G. P. Vacca and G. Venturi},
journal= {arXiv preprint arXiv:gr-qc/0407101},
year = {2008}
}
Comments
5 pages, revtex, final version accepted for publication in PRD