Spatial Statistics and Cosmology: Measuring Dark Matter Distortions of the Cosmic Microwave Background

• Activity Number: 661
• Type: Invited
• Date/Time: Thursday, August 8, 2013 : 10:30 AM to 12:20 PM
• Sponsor: IMS
• Author(s): Ethan Berger Anderes*+
• Companies: University of California at Davis
• Keywords: Spatial statistics ; cosmology ; weak lensing ; quadratic estimator ; random fields ; dark matter

Abstract

Recent data from two ground based telescopes, ACT and SPT, have resulted in the first direct detection of dark matter distortions of the cosmic microwave background (CMB) from CMB measurements alone. In the coming years, the data on the CMB from Plank and upcoming experiments ACTpol and SPTpol will begin probing this lensing at much greater resolution and is projected to have a large impact on the understanding of the origins of our universe. The state-of-the-art estimator of weak lensing, the quadratic estimator developed by Hu and Okomoto (2001, 2002), works in part through a delicate cancelation of terms in a Taylor expansion of the lensing effect on the CMB. In this talk we give a general overview of the quadratic estimator and present a simulation based approach for exploring the nature of Taylor expansion cancelation for both the CMB intensity and the polarization fields. The methodology we present---which allows an easy exploration of higher order bias terms---also has the potential to reduce the computational load associated with iterative de-biasing algorithms for the quadratic estimate.