2015/02/28 by Jessica L. Cook, Emanuela Dimastrogiovanni, Damien A. Easson +1 · 4 citations
Physics and Astronomy · #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1088/1475-7516/2015/04/047
32 pages, 15 figures. Revised in response to comments on the original version, and in preparation for submission for publication. More references and a new figure were added
arxiv created 2015/03/10 · arxiv updated 2015/06/23
Reheating is a transition era after the end of inflation, during which the inflaton is converted into the particles that populate the Universe at later times. No direct cosmological observables are normally traceable to this period of reheating. Indirect bounds can however be derived. One possibility is to consider cosmological evolution for observable CMB scales from the time of Hubble crossing to the present time. Depending upon the model, the duration and final temperature after reheating, as well as its equation of state, may be directly linked to inflationary observables. For single-field inflationary models, if we approximate reheating by a constant equation of state, one can derive relations between the reheating duration (or final temperature), its equation of state parameter, and the scalar power spectrum amplitude and spectral index. While this is a simple approximation, by restricting the equation of state to lie within a broad physically allowed range, one can in turn bracket an allowed range of ns and r for these models. The added constraints can help break degeneracies between inflation models that otherwise overlap in their predictions for ns and r.