Distortions in the surface of last scattering

Journal Article · 01 August 2019 · Physical Review D

DOI: https://doi.org/10.1103/PhysRevD.100.043502 · OSTI ID:1595730

Li, Peikai  ^[1]; Dodelson, Scott ^[2]; Hu, Wayne ^[3]

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1. Carnegie Mellon Univ., Pittsburgh, PA (United States); University of Chicago
2. Carnegie Mellon Univ., Pittsburgh, PA (United States)
3. Univ. of Chicago, IL (United States). Enrico Fermi Inst., Kavli Inst. for Cosmological Physics

The surface of last scattering of the photons in the cosmic microwave background is not a spherical shell. Apart from its finite width, each photon experiences a different gravitational potential along its journey to us, leading to different travel times in different directions. Photons passing through an underdense region started farther away from us than those traveling through an overdense region. Thus, the surface of last scattering is corrugated, a deformed spherical shell. Here, we present an estimator quadratic in the temperature and polarization fields that could provide a map of the time delays as a function of position on the sky. The signal to noise of this map could exceed unity for the dipole, thereby providing a rare insight into the universe on the largest observable scales.

• Research Organization: Univ. of Chicago, IL (United States); Carnegie Mellon Univ., Pittsburgh, PA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP); National Aeronautics and Space Administration (NASA); Simons Foundation
• Grant/Contract Number: SC0009924; SC0019248; SC0010118
• OSTI ID: 1595730
• Journal Information: Physical Review D, Journal Name: Physical Review D Journal Issue: 4 Vol. 100; ISSN PRVDAQ; ISSN 2470-0010
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English