Constraints on large-scale polarization in northern hemisphere

TL;DR

This paper explores the potential of a northern hemisphere CMB polarization telescope to detect primordial gravitational waves, forecasting its sensitivity and optimal configurations to improve constraints on the tensor-to-scalar ratio.

Contribution

It presents a mock data analysis and sensitivity forecast for a northern hemisphere CMB polarization telescope, highlighting its potential to enhance primordial gravitational wave detection.

Findings

NHT combined with Planck can achieve .015 sensitivity in the first year

Optimal configurations can significantly improve detection sensitivity

NHT has comparable sensitivity to existing southern experiments

Abstract

Present cosmic microwave background (CMB) observations have significantly advanced our understanding of the universe's origin, especially with primordial gravitational waves (PGWs). Currently, ground-based CMB telescopes are mainly located in the southern hemisphere, leaving an untapped potential for observations in the northern hemisphere. In this work, we investigate the perspective of a northern hemisphere CMB polarization telescope (NHT) to detect PGWs and present mock data for such a project. We forecast the detection sensitivity on the tensor-to-scalar ratio r of NHT and compare it with the existed ground-based experiments, also search for optimal experimental configurations that can achieve the best sensitivity of r. Our results indicate that, considering realistic experimental conditions, the first year of NHT observations combined with Planck can achieve a precision of \sigma (r)= 0.015, reaching the level of BICEP2/Keck, with significant potential for improvement with subsequent instrumentation parameter enhancements.