Experimental radio astronomy for CMB studies

Abstract: 
The Cosmic Microwave Background (CMB) is a treasure trove of information about the Universe and the physics that governs it. Two open problems in cosmology are those of cosmic inflation and cosmic dawn (CD) - epoch of reionization (EoR). High sensitivity measurements of the CMB polarization and spectrum will enable addressing these problems and build a more complete picture of the Universe and its history. I will discuss radio frequency experiments and methods being employed to detect these faint signals. Specifically, I will discuss multiplexing of superconducting photon detectors for CMB polarization studies employed in the upcoming Simons Observatory (SO) telescope; and efforts to detect the global signal resulting from CD-EoR as a distortion in CMB spectrum with the proposed lunar orbiter experiment - PRATUSH. I will also make the case to apply a combination of techniques used in SO and PRATUSH to detect the inevitable distortion in the CMB spectrum arising from the formation of the first atoms in the Universe over the cosmological epoch of recombination.