title: Demonstration of Cosmic Microwave Background Delensing Using the Cosmic Infrared Background.
abstract: Delensing is an increasingly important technique to reverse the gravitational lensing of the cosmic microwave background (CMB) and thus reveal primordial signals the lensing may obscure. We present a first demonstration of delensing on Planck temperature maps using the cosmic infrared background (CIB). Reversing the lensing deflections in Planck CMB temperature maps using a linear combination of the 545 and 857 GHz maps as a lensing tracer, we find that the lensing effects in the temperature power spectrum are reduced in a manner consistent with theoretical expectations. In particular, the characteristic sharpening of the acoustic peaks of the temperature power spectrum resulting from successful delensing is detected at a significance of 16σ, with an amplitude of A_{delens}=1.12±0.07 relative to the expected value of unity. This first demonstration on data of CIB delensing, and of delensing techniques in general, is significant because lensing removal will soon be essential for achieving high-precision constraints on inflationary B-mode polarization.
authors: Institute of Astronomy and Kavli Institute for Cosmology Cambridge, Madingley Road, Cambridge CB3 0HA, United Kingdom.
authors: Patricia
authors: P
authors: Larsen
authors: Institute of Astronomy and Kavli Institute for Cosmology Cambridge, Madingley Road, Cambridge CB3 0HA, United Kingdom.|DAMTP, Centre for Mathematical Sciences, Wilberforce Road, Cambridge CB3 0WA, United Kingdom.
authors: Anthony
authors: A
authors: Challinor
authors: Department of Physics, University of California, Berkeley, California 94720, USA.|Miller Institute for Basic Research in Science, University of California, Berkeley, California 94720, USA.
authors: Blake D
authors: BD
authors: Sherwin
authors: Institute of Astronomy and Kavli Institute for Cosmology Cambridge, Madingley Road, Cambridge CB3 0HA, United Kingdom.
authors: Daisy
authors: D
authors: Mak