A Cautionary Tale: Dark Energy in Single-Field, Slow-Roll Inflationary Models
| Autor: | Castello, Sveva, Ilić, Stéphane, Kunz, Martin |
|---|---|
| Přispěvatelé: | HEP, INSPIRE |
| Rok vydání: | 2022 |
| Předmět: |
satellite: Planck
cosmological constant Cosmology and Nongalactic Astrophysics (astro-ph.CO) space-time: expansion [PHYS.GRQC] Physics [physics]/General Relativity and Quantum Cosmology [gr-qc] inflation: slow-roll approximation FOS: Physical sciences hierarchy Astrophysics::Cosmology and Extragalactic Astrophysics General Relativity and Quantum Cosmology (gr-qc) BICEP inflation: model inflaton General Relativity and Quantum Cosmology field theory: scalar confidence limit expansion: acceleration dark energy [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph] equation of state Astrophysics - Cosmology and Nongalactic Astrophysics |
| DOI: | 10.48550/arxiv.2203.08762 |
| Popis: | The current epoch of accelerated cosmic expansion is postulated to be driven by dark energy, which in the standard model takes the form of a cosmological constant with equation of state parameter $w=-1$. We propose an innovative perspective over the nature of dark energy by drawing a parallel with inflation, which we assume to be driven by a single scalar field, the inflaton. The inflaton was not a cosmological constant, as indicated by the fact that inflation ended and by the Planck satellite's constraint of $n_s\neq 1$ at $8\sigma$ confidence. Therefore, it is interesting to verify whether its equation of state parameter was measurably different from $-1$. We analyze this question for a class of single-field slow-roll inflationary models, where the hierarchy of Hubble slow-roll parameters is truncated at different orders. Based on the latest Planck and BICEP2/Keck data, we obtain a $68\%$ upper bound of $1+w < 0.0014$ for the three-parameter model, which gives the best description to the data. This provides a cautionary tale for drawing conclusions about the nature of today's dark energy based upon the non-detection of a deviation from $w=-1$ with current and upcoming cosmological surveys. Comment: Contribution to the 2022 Cosmology session of the 56th Rencontres de Moriond |
| Databáze: | OpenAIRE |
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