Probing reheating with primordial spectrum

TL;DR

This paper investigates how the reheating temperature after inflation affects predictions of the spectral index and tensor-to-scalar ratio, finding constraints and insensitivities in certain models.

Contribution

It provides a detailed analysis of reheating temperature impacts on inflationary predictions, including constraints for sinusoidal oscillations and insensitivity in models like Higgs inflation.

Findings

Reheating temperature can be constrained within a factor of 10-100 for sinusoidal oscillations.

Predictions can be insensitive to reheating temperature in some models, such as Higgs inflation.

Future observations could improve constraints on reheating temperature.

Abstract

We study the impacts of reheating temperature on the inflationary predictions of the spectral index and tensor-to-scalar ratio. Assuming sinusoidal oscillations and that reheating process is very fast, the reheating temperature can be constrained for sinusoidal oscillation within a factor of 10 - 100 or even better with the prospect of future observations. Beyond this, we find that the predictions can also be insensitive to the reheating temperature in certain models, including Higgs inflation.