Observational Cosmology Seminar

The standard tool for reconstructing the lensing potential of the Cosmic Microwave Background from observational data is the quadratic estimator. While this method has enjoyed a remarkable amount of success, it is susceptible to bias caused by anisotropy in foregrounds, noise, and masking procedures. I will give an overview of the standard quadratic estimator, and then I will introduce a new quadratic estimator, the "shear-only" estimator, that is constructed to be less susceptible to biases. I will discuss the benefits and drawbacks of this new estimator, and comment on its prospects for future data analyses.