Back to the features: assessing the discriminating power of future CMB missions on inflationary models

TL;DR

Future CMB experiments will significantly enhance our ability to detect and distinguish primordial features related to inflation, potentially confirming or ruling out current anomalies with high statistical confidence.

Contribution

This study uses advanced forecasting methods to evaluate how upcoming CMB missions can test and differentiate inflationary models involving primordial features.

Findings

Future experiments can detect primordial features with high significance.

They can discriminate between different inflationary models.

Current anomalies may be confirmed or dismissed based on upcoming data.

Abstract

Future Cosmic Microwave Background (CMB) experiments will deliver extremely accurate measurements of the E-modes pattern of the CMB polarization field. Given the sharpness of the E-modes transfer functions, such surveys make for a powerful detector of high-frequency signals from primordial features that may be lurking in current data sets. With a handful of toy models that increase the fit to the latest Planck data, but are of marginal statistical significance, we use a state-of-the-art forecast pipeline to illustrate the promising prospects to test primordial features in the next decade. Not only will future experiments allow us to detect such features in data, but they will also be able to discriminate between models and narrow down the physical mechanism originating them with high statistical significance. On the other hand, if the anomalies in the currently measured CMB spectra are just statistical fluctuations, all the current feature best fit candidates will be ruled out. Either way, our results show that primordial features are a clear target of forthcoming CMB surveys beyond the detection of tensor modes.