Astro Seminar: "Understanding large-scale structure from the CMB"

Wed, 10/19/2016 - 14:00 - 15:00
Emmanuel Schaan (Princeton)

In this seminar, I will present two ways in which the cosmic microwave background (CMB) sheds light on critical uncertain physics and systematics of the large-scale structure.

Shear calibration with CMB lensing (arXiv:1607.01761):

Realizing the full potential of upcoming weak lensing surveys requires an exquisite understanding of the errors in galaxy shape estimation. In particular, such errors lead to a multiplicative bias in the shear, degenerate with cosmology. Its redshift-evolution can hide the true evolution of the growth of structure, which probes dark energy and possible modifications to general relativity. I will show that CMB lensing from a stage 4 experiment (CMB S4) can self-calibrate the shear for an LSST-like optical lensing experiment. This holds in the presence of photo-z errors and intrinsic alignment.

Evidence for the kinematic Sunyaev-Zel'dovich (kSZ) effect; cluster energetics (arXiv:1510.06442):

Through the kSZ effect, the baryon momentum field is imprinted on the CMB. I will report significant evidence for the kSZ effect from ACTPol and peculiar velocities reconstructed from BOSS. I will present the prospects for constraining cluster gas profiles and energetics from the kSZ effect with SPT-3G, AdvACT and CMB S4.

David Rittenhouse Laboratory, A4