The Cosmology Large Angular Scale Surveyor (CLASS) is an array of polarization-sensitive millimeter wave telescopes that observes ∼70% of the sky at frequency bands centered near 40GHz, 90GHz, 150GHz, and 220GHz from the Atacama desert of northern Chile. The primary science goals of CLASS are two-fold: to search for polarization B-modes in the cosmic microwave background (CMB) as strong evidence of cosmological inflation and to make a measurement of the optical depth due to reionization, via polarization E-modes, to near the cosmic variance limit. In this talk, I will discuss the science goals of CLASS and its instrument design, including my contribution to it. Then, I will cover the modeling of atmospheric circular polarization due to Zeeman splitting of molecular oxygen in the geomagnetic field and the detection of said polarization with CLASS. Finally, I will discuss the development of a machine learning method for the cleaning of CMB foregrounds from full-sky maps.

Via Zoom:  https://princeton.zoom.us/j/94697671484