CMB interferometry

TL;DR

Interferometry has been crucial in advancing CMB research, enabling measurements of anisotropies, polarization, and the Sunyaev-Zel'dovich effect, with future prospects in high-redshift HI intensity mapping.

Contribution

This review highlights the key role of interferometry in CMB studies and discusses future applications like HI intensity mapping at high redshifts.

Findings

First detection of CMB polarization by DASI in 2002.

Major contributions to small-scale anisotropy measurements.

Detection and survey of the Sunyaev-Zel'dovich effect in galaxy clusters.

Abstract

Interferometry has been a very successful tool for measuring anisotropies in the cosmic microwave background. Interferometers provided the first constraints on CMB anisotropies on small angular scales (l~10000) in the 1980s and then in the late 1990s and early 2000s made ground-breaking measurements of the CMB power spectrum at intermediate and small angular scales covering the l-range ~100-4000. In 2002 the DASI made the first detection of CMB polarization which remains a major goal for current and future CMB experiments. Interferometers have also made major contributions to the detection and surveying of the Sunyaev-Zel'dovich (SZ) effect in galaxy clusters. In this short review I cover the key aspects that made interferometry well-suited to CMB measurements and summarise some of the central observations that have been made. I look to the future and in particular to HI intensity mapping at high redshifts that could make use of the advantages of interferometry.