Bayesian analysis for a class of $\alpha$-attractor inflationary models

Abstract

We perform a Bayesian study of a generalization of the basic $\alpha$-attractor T model given by the potential $V(\varphi )=V_0\left[1-{\text{sech}}^p\left(\varphi /\sqrt{6\alpha }{M}_{pl}\right)\right]$ where $\varphi$ is the inflaton field and the parameter $\alpha$ corresponds to the inverse curvature of the scalar manifold in the conformal or superconformal realizations of the attractor models. Such generalization is characterized by the power $p$ which includes the basic or base model for $p=2$. Once the priors for the parameters of the $\alpha$-attractor potential are set by numerical exploration, we perform the corresponding statistical analysis for the cases $p=1,2,3,4$, and derive posteriors. Considering the original $\alpha$-attractor potential as the base model, we calculate the evidence for our generalization, and conclude that the $p=4$ model is preferred by the CMB data. We also present constraints for the parameter $\alpha$. Interestingly, all the cases studied prefer a specific value for the tensor-to-scalar ratio given by $r\simeq 0.0025$.

arXiv comment17 pages, 8 figures, 4 tables. Minor amendments to match the version published in JCAP

References in corpus (31)

• MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
• Planck 2018 results. X. Constraints on inflation
• Nine-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Final Maps and Results
• Multimodal nested sampling: an efficient and robust alternative to MCMC methods for astronomical data analysis
• Encyclopaedia Inflationaris
• Importance Nested Sampling and the MultiNest Algorithm
• Conservative Constraints on Early Cosmology: an illustration of the Monte Python cosmological parameter inference code
• Superconformal Inflationary $\alpha$-Attractors
• PolyChord: nested sampling for cosmology
• PolyChord: next-generation nested sampling
• First CMB Constraints on the Inflationary Reheating Temperature
• The Best Inflationary Models After Planck
• Reheating constraints to inflationary models
• Improved limits on the tensor-to-scalar ratio using BICEP and Planck
• Improved measurements of the temperature and polarization of the CMB from QUaD
• Measurement of Cosmic Microwave Background Polarization Power Spectra from Two Years of BICEP Data
• Dark energy, $\alpha$-attractors, and large-scale structure surveys
• Properties of Nested Sampling
• Measurements of B-mode Polarization of the Cosmic Microwave Background from 500 Square Degrees of SPTpol Data
• Second Season QUIET Observations: Measurements of the CMB Polarization Power Spectrum at 95 GHz
• Computational methods for Bayesian model choice
• Revisiting small-scale fluctuations in $\alpha$-attractor models of inflation
• Polynomial $\alpha$-attractors
• Quintessential $\alpha$-attractor inflation: forecasts for Stage IV galaxy surveys
• Bayesian evidence for $\alpha$-attractor dark energy models
• Observational constraints on $\alpha$-attractor inflationary models with a Higgs-like potential
• Theoretical and observational constraints on Tachyon Inflation
• (P)reheating and gravitational waves in $\alpha$-attractor models
• New generalization of the simplest $\alpha$-attractor $T$ model
• Current and Future constraints on single-field $\alpha$-Attractor model
• A simple supergravity model of inflation constrained with Planck 2018 data

Cited by in corpus (1)

• Development of generic no-scale inflation