2002/09/26 by Nemanja Kaloper, Matthew Kleban, Albion Lawrence +2 · 1 citation
Physics and Astronomy · #hep-th #astro-ph #gr-qc #hep-ph
paper · pdf · doi:10.1088/1126-6708/2002/11/037
published as JHEP 0211:037,2002 · 31 pages, 4 figures
arxiv created 2002/09/26 · arxiv updated 2009/11/30
Free scalar fields in de Sitter space have a one-parameter family of states invariant under the de Sitter group, including the standard thermal vacuum. We show that, except for the thermal vacuum, these states are unphysical when gravitational interactions are included. We apply these observations to the quantum state of the inflaton, and find that, at best, dramatic fine tuning is required for states other than the thermal vacuum to lead to observable features in the CMBR anisotropy.