Cosmic Inflation at the crossroads
Apr 16, 2024
79 pages
Published in:
- JCAP 07 (2024) 087
- Published: Jul 31, 2024
e-Print:
- 2404.10647 [astro-ph.CO]
View in:
Citations per year
Abstract: (IOP)
The capability of Cosmic Inflation to explain the latestCosmic Microwave Background and Baryonic Acoustic Oscillation datais assessed by performing Bayesian model comparison within thelandscape of nearly three-hundred models of single-field slow-rollinflation. We present the first Bayesian data analysis based on thethird-order slow-roll primordial power spectra. In particular, thefourth Hubble-flow function ε remains unbounded while thethird function verifies, at two-sigma, ε ∈[-0.4,0.5],which is perfectly compatible with the slow-roll predictions for therunning of the spectral index. We also observe some residual excessof B-modes within the BICEP/Keck data favoring, at anon-statistically significant level, non-vanishing primordial tensormodes: log(ε) > -3.9, at 68% confidence level. Then,for 287 models of single-field inflation, we compute the Bayesianevidence, the Bayesian dimensionality and the marginalizedposteriors of all the models' parameters, including the onesassociated with the reheating era. The average information gain onthe reheating parameter R reaches 1.3 ± 0.18 bits, whichis more than a factor two improvement compared to the first Planckdata release. As such, inflationary model predictions cannot meetdata accuracy without specifying, or marginalizing over, thereheating kinematics. We also find that more than 40% of thescenarios are now strongly disfavored, which shows that theconstraining power of cosmological data is winning against theincrease of the number of proposed models. In addition, about 20%of all models have evidences within the most probable region and areall favored according to the Jeffreys' scale of Bayesian evidences.Note:
- 79 pages, 37 figures, uses jcappub. Discussions added, matches published version
- Inflation and CMBR theory
- Bayesian reasoning
- CMBR theory
- cosmological parameters from CMBR
- inflation: slow-roll approximation
- power spectrum: primordial
- inflation: model
- baryon: oscillation: acoustic
- statistical analysis: Bayesian
- reheating
References(130)
Figures(39)
- [1]
- [2]
- [3]
- [4]
- [5]
- [6]
- [7]
- [8]
- [9]
- [10]
- [11]
- [12]
- [13]
- [14]
- [15]
- [16]
- [17]
- [18]
- [19]
- [20]
- [21]
- [22]
- [23]
- [24]
- [25]