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Getting around cosmic variance
- Source :
- Physical Review D. 56:4511-4513
- Publication Year :
- 1997
- Publisher :
- American Physical Society (APS), 1997.
-
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 SLSs 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 SLSs within the observable Universe, and hence reduce the cosmic-variance uncertainty.<br />Comment: 6 pages, RevTeX, with two postscript figures
- Subjects :
- Physics
Nuclear and High Energy Physics
media_common.quotation_subject
Astrophysics (astro-ph)
Cosmic microwave background
Astrophysics::Instrumentation and Methods for Astrophysics
FOS: Physical sciences
Astronomy
Cosmic ray
Observable universe
Astrophysics::Cosmology and Extragalactic Astrophysics
Cosmic variance
Astrophysics
Particle horizon
Universe
Caltech Library Services
Galaxy cluster
Background radiation
media_common
Subjects
Details
- ISSN :
- 10894918 and 05562821
- Volume :
- 56
- Database :
- OpenAIRE
- Journal :
- Physical Review D
- Accession number :
- edsair.doi.dedup.....4a2b3ec6356d0203bd7118cd2e0fada8