TY - JOUR
T1 - Reconstructing the primary CMB dipole
AU - Meerburg, P. Daniel
AU - Meyers, Joel
AU - Van Engelen, Alexander
N1 - Funding Information:
We would like to thank Nick Battaglia, Anthony Challinor, Jens Chluba, Simone Ferraro, Matt Johnson, Arthur Kosowsky, Niels Oppermann, Guilherme Pimentel, Douglas Scott, Kendrick Smith, and David Spergel for discussions. J. M. was supported by the Vincent and Beatrice Tremaine Fellowship.
Publisher Copyright:
© 2017 American Physical Society.
PY - 2017/10/15
Y1 - 2017/10/15
N2 - The observed dipole anisotropy of the cosmic microwave background (CMB) temperature is much larger than the fluctuations observed on smaller scales, and it is dominated by the kinematic contribution from the Doppler boosting of the monopole due to our motion with respect to the CMB rest frame. In addition to this kinematic component, there is expected to be an intrinsic contribution with an amplitude about two orders of magnitude smaller. Here we explore a method whereby the intrinsic CMB dipole can be reconstructed through observation of temperature fluctuations on small scales that result from gravitational lensing. Though the experimental requirements pose practical challenges, we show that one can, in principle, achieve a cosmic variance limited measurement of the primary dipole using the reconstruction method we describe. Since the primary CMB dipole is sensitive to the largest observable scales, such a measurement would have a number of interesting applications for early universe physics, including testing large-scale anomalies, extending the lever-arm for measuring local non-Gaussianity, and constraining isocurvature fluctuations on superhorizon scales.
AB - The observed dipole anisotropy of the cosmic microwave background (CMB) temperature is much larger than the fluctuations observed on smaller scales, and it is dominated by the kinematic contribution from the Doppler boosting of the monopole due to our motion with respect to the CMB rest frame. In addition to this kinematic component, there is expected to be an intrinsic contribution with an amplitude about two orders of magnitude smaller. Here we explore a method whereby the intrinsic CMB dipole can be reconstructed through observation of temperature fluctuations on small scales that result from gravitational lensing. Though the experimental requirements pose practical challenges, we show that one can, in principle, achieve a cosmic variance limited measurement of the primary dipole using the reconstruction method we describe. Since the primary CMB dipole is sensitive to the largest observable scales, such a measurement would have a number of interesting applications for early universe physics, including testing large-scale anomalies, extending the lever-arm for measuring local non-Gaussianity, and constraining isocurvature fluctuations on superhorizon scales.
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U2 - 10.1103/PhysRevD.96.083519
DO - 10.1103/PhysRevD.96.083519
M3 - Article
AN - SCOPUS:85033212249
SN - 2470-0010
VL - 96
JO - Physical Review D
JF - Physical Review D
IS - 8
M1 - 083519
ER -