Getting around cosmic variance
- Creators
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Kamionkowski, Marc
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Loeb, Abraham
Abstract
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.
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.Files
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Additional details
- Eprint ID
- 3465
- Resolver ID
- CaltechAUTHORS:KAMprd97b
- Created
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2006-06-08Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field