{"work":{"id":"6a5d00a7-0d0f-4323-a502-0aa5a2c1e708","openalex_id":null,"doi":null,"arxiv_id":"1404.6704","raw_key":null,"title":"Reheating constraints to inflationary models","authors":null,"authors_text":"L","year":2014,"venue":"astro-ph.CO","abstract":"Evidence from the BICEP2 experiment for a significant gravitational-wave background has focussed attention on inflaton potentials $V(\\phi) \\propto \\phi^\\alpha$ with $\\alpha=2$ (\"chaotic\" or \"$m^2\\phi^2$\" inflation) or with smaller values of $\\alpha$, as may arise in axion-monodromy models. Here we show that reheating considerations may provide additional constraints to these models. The reheating phase preceding the radiation era is modeled by an effective equation-of-state parameter $w_{\\rm re}$. The canonical reheating scenario is then described by $w_{\\rm re}=0$. The simplest $\\alpha=2$ models are consistent with $w_{\\rm re} = 0$ for values of $n_s$ well within the current $1\\sigma$ range. Models with $\\alpha=1$ or $\\alpha=2/3$ require a more exotic reheating phase, with $-1/3<w_{\\rm re}<0$, unless $n_s$ falls above the current $1\\sigma$ range. Likewise, models with $\\alpha=4$ require a physically implausible $w_{\\rm re}>1/3$, unless $n_s$ is close to the lower limit of the $2\\sigma$ range. For $m^2\\phi^2$ inflation and canonical reheating as a benchmark, we derive a relation $\\log_{10}\\left(T_{\\rm re}/10^6\\,{\\rm GeV} \\right) \\simeq 2000\\,(n_s-0.96)$ between the reheat temperature $T_{\\rm re}$ and the scalar spectral index $n_s$. Thus, if $n_s$ is close to its central value, then $T_{\\rm re}\\lesssim 10^6$~GeV, just above the electroweak scale. If the reheat temperature is higher, as many theorists may prefer, then the scalar spectral index should be closer to $n_s\\simeq0.965$ (at the pivot scale $k=0.05\\,{\\rm Mpc}^{-1}$), near the upper limit of the $1\\sigma$ error range. Improved precision in the measurement of $n_s$ should allow $m^2\\phi^2$, axion-monodromy, and $\\phi^4$ models to be distinguished, even without precise measurement of $r$, and to test the $m^2\\phi^2$ expectation of $n_s\\simeq0.965$.","external_url":"https://arxiv.org/abs/1404.6704","cited_by_count":null,"metadata_source":"pith","metadata_fetched_at":"2026-05-25T00:00:07.523518+00:00","pith_arxiv_id":"1404.6704","created_at":"2026-05-10T05:46:10.083361+00:00","updated_at":"2026-05-25T00:00:07.523518+00:00","title_quality_ok":true,"display_title":"Reheating constraints to inflationary models","render_title":"Reheating constraints to inflationary models"},"hub":{"state":{"work_id":"6a5d00a7-0d0f-4323-a502-0aa5a2c1e708","tier":"hub","tier_reason":"10+ Pith inbound or 1,000+ external citations","pith_inbound_count":11,"external_cited_by_count":null,"distinct_field_count":3,"first_pith_cited_at":"2019-07-09T20:36:00+00:00","last_pith_cited_at":"2026-05-19T13:18:35+00:00","author_build_status":"not_needed","summary_status":"needed","contexts_status":"needed","graph_status":"needed","ask_index_status":"not_needed","reader_status":"not_needed","recognition_status":"not_needed","updated_at":"2026-05-31T06:52:11.583248+00:00","tier_text":"hub"},"tier":"hub","role_counts":[{"context_role":"background","n":4}],"polarity_counts":[{"context_polarity":"background","n":4}],"runs":{},"summary":{},"graph":{},"authors":[]}}