Institute of Astronomy

CMB Lensing: Fundamental Physics from Maps of the Invisible

SpeakerTalk DateTalk Series
Blake Sherwin (DAMTP)23 November 2017Institute of Astronomy Colloquia

Abstract

Dark matter not only forms an invisible cosmic scaffolding within which
galaxies form, its distribution in the universe also contains a wealth of
information about neutrinos, dark energy, and physics at the earliest times.
Measurements of gravitational lensing in the cosmic microwave background
(CMB) allow this matter distribution to be directly seen and mapped.  In my
talk, I will first discuss recent measurements of CMB lensing and their
scientific implications. I will then explain why upcoming measurements of
the CMB lensing signal, with experiments such as AdvancedACT and Simons
Observatory, will be remarkably powerful probes of cosmology. Lensing is not
only a signal, however, but also a source of noise that limits how much we
can learn about the very early universe. With illustrations from recent
work, I will explain why delensing - removing the lensing effect to reveal
the primordial sky - is crucial for the future of CMB cosmology.

Presentation

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