Quadratic chaotic inflation with a logarithmic-corrected mass

TL;DR

This paper modifies quadratic chaotic inflation by adding a logarithmic correction to the mass term, aligning the model with recent cosmological data and predicting testable tensor-to-scalar ratios in future CMB polarization observations.

Contribution

It introduces a novel logarithmic correction to the inflationary potential and analyzes its compatibility with current observations, also exploring higher-order corrections and their observational signatures.

Findings

Model consistent with Planck 2018, BICEP2/Keck, and BAO data.

Predicts a lower limit for the tensor-to-scalar ratio r.

Different correction forms occupy distinct parameter space regions.

Abstract

We consider a simple modification of quadratic chaotic inflation. We add a logarithmic correction to the mass term, and find that this model can be consistent with the latest cosmological observations such as the Planck 2018 data, in combination with the BICEP2/Keck Array and the baryon acoustic oscillation data. Since the model predicts the lower limit for the tensor-to-scalar ratio r for the present allowed values of the spectral index n_s, it could be tested by the cosmic microwave background polarization observation in the near future. In addition, we consider higher-order logarithmic corrections. Interestingly, we observe that the scalar spectral index n_s and r stay in rather a narrow region of the parameter space. Moreover, they reside in a completely different region from that for the logarithmic corrections to the quartic coupling. Therefore, future observations may distinguish which kind of corrections should be included, or even single out the form of the interactions.