1. Can relic superhorizon inhomogeneities be responsible for large-scale CMB anomalies?
- Author
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Gao, Xian
- Subjects
- *
COSMIC background radiation , *FLUCTUATIONS (Physics) , *QUADRUPOLES , *ANISOTROPY , *SPECTRUM analysis , *QUANTUM perturbations - Abstract
Abstract: We investigate the effects of the presence of relic classical superhorizon inhomogeneities during inflation. This superhorizon inhomogeneity appears as a gradient locally and picks out a preferred direction. Quantum fluctuations on this slightly inhomogeneous background are generally statistical anisotropic. We find a quadrupole modification to the ordinary isotropic spectrum. Moreover, this deviation from statistical isotropy is scale-dependent, with a factor. This result implies that the statistical anisotropy mainly appears on large scales, while the spectrum on small scales remains highly isotropic. Moreover, due to this factor, the power on large scales is suppressed. Thus, our model can simultaneously explain the observed anisotropic alignments of the low-ℓ multipoles and their low power. [Copyright &y& Elsevier]
- Published
- 2011
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