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Getting around cosmic variance

Kamionkowski, Marc and Loeb, Abraham (1997) Getting around cosmic variance. Physical Review D, 56 (8). pp. 4511-4513. ISSN 2470-0010. doi:10.1103/PhysRevD.56.4511.

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Cosmic microwave background (CMB) anisotropies probe the primordial density field at the edge of the observable Universe. There is a limiting precision (“cosmic variance”) with which anisotropies can determine the amplitude of primordial mass fluctuations. This arises because the surface of last scatter (SLS) probes only a finite two-dimensional slice of the Universe. Probing other SLS's observed from different locations in the Universe would reduce the cosmic variance. In particular, the polarization of CMB photons scattered by the electron gas in a cluster of galaxies provides a measurement of the CMB quadrupole moment seen by the cluster. Therefore, CMB polarization measurements toward many clusters would probe the anisotropy on a variety of SLS's within the observable Universe, and hence reduce the cosmic-variance uncertainty.

Item Type:Article
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URLURL TypeDescription
Kamionkowski, Marc0000-0001-7018-2055
Loeb, Abraham0000-0003-4330-287X
Additional Information:©1997 The American Physical Society Received 16 May 1997 We thank U.-L. Pen and U. Seljak for useful comments. This work was supported at Columbia University by U.S. DOE Contract No. DEFG02-92-ER 40699, NASA ATP Grant No. NAG5-3091, and the Alfred P. Sloan Foundation, and at Harvard University by NASA ATP Grant No. NAG5-3085 and the Harvard Milton fund.
Issue or Number:8
Record Number:CaltechAUTHORS:KAMprd97b
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:3465
Deposited By: Archive Administrator
Deposited On:08 Jun 2006
Last Modified:08 Nov 2021 19:56

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