2006/12/31 by E. O. Kahya, V. K. Onemli · 1 citation
Physics and Astronomy · #gr-qc #astro-ph #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.76.043512
published as Phys.Rev.D76:043512,2007 · 23 pages
arxiv created 2007/08/15 · arxiv updated 2009/12/01
We consider a massless, minimally coupled scalar with a quartic self-interaction which is released in Bunch-Davies vacuum in locally de Sitter background of an inflating universe. It was shown, in this system, that quantum effects can induce a temporary phase of super-acceleration causing a violation of the Weak Energy Condition on cosmological scales. In this paper we investigate the system's stability by studying the behavior of linearized perturbations in the quantum-corrected effective field equation at one and two-loop order. We show that the time dependence we infer from the quantum-corrected mode function is in perfect agreement with the system developing a positive mass squared. The maximum induced mass remains perturbatively small and it does not go tachyonic. Thus, the system is stable.