The CMB polarization: status and prospects

Clover - A B-mode polarization experiment

Clover is a new instrument being built to detect the B-mode polarization of the CMB. It consists of three telescopes operating at 97, 150, and 220 GHz and will be sited in Chile at the Llano de Chajnantor. Each telescope assembly is scaled to give a constant beam size of 8 arcmin and feeds an array of between 320 and 512 finline-coupled TES bolometers. Here we describe the design, current statu...

CMB Optical Depth Measurements: Past, Present, Future

The polarization of the cosmic microwave background (CMB) is encoded with exactly the same cosmic information as the CMB’s temperature anisotropy. However, polarization has the additional promise of accurately probing the reionization history of the universe and potentially constraining, or detecting, the primordial background of gravitational waves produced by inflation. We demonstrate that th...

Detecting dark matter annihilation with CMB polarization: Signatures and experimental prospects

A CMB Polarization Primer

We present a pedagogical and phenomenological introduction to the study of cosmic microwave background (CMB) polarization to build intuition about the prospects and challenges facing its detection. Thomson scattering of temperature anisotropies on the last scattering surface generates a linear polarization pattern on the sky that can be simply read off from their quadrupole moments. These in tu...

Delensing CMB Polarization with External Datasets

One of the primary scientific targets of current and future CMB polarization experiments is the search for a stochastic background of gravity waves in the early universe. As instrumental sensitivity improves, the limiting factor will eventually be B-mode power generated by gravitational lensing, which can be removed through use of so-called “delensing” algorithms. We forecast prospects for dele...