Siddharth Malu (The Inter-University Centre for Astronomy and Astrophysics, Pune)

A Novel Approach to finding B-modes in CMB Polarization - Siddharth Malu Colloquium

ATNF Marsfield Lecture Theatre

Abstract

CMB studies are now a data-rich field in astrophysics. The power spectrum of CMB is well measured and cosmological models have been characterized and polarization has been detected in the CMB. All results fit well within and are explained well by the inflationary paradigm. But current evidence for inflation is indirect. The next generation of CMB experiments will aim at providing the most direct evidence for inflation through the detection of B-modes in CMB polarization. Despite improvements in experimental techniques, it is as yet unclear what configuration and approach a CMB polarization experiment should adopt, in view of lack of information about polarization foregrounds and instrument systematic effects. I will describe a novel approach to these measurements, called bolometric interferometry, which avoids many of the systematic errors found in imaging systems. In particular, I will describe a prototype, the Millimeter-wave Bolometric Interferometer (MBI). I will present a few promising approaches from our collaboration, the Q-and-U Bolometric Interferometer for Cosmology (QUBIC) and discuss plans for feasibility studies for detecting CMB polarization foregrounds and signals with adding interferometers.