Gao, X (reprint author), Chinese Acad Sci, Inst Theoret Phys, Key Lab Frontiers Theoret Phys, 55 Zhong Guan Cun E Rd, Beijing 100080, Peoples R China.
部门归属:
Chinese Acad Sci, Inst Theoret Phys, Key Lab Frontiers Theoret Phys, Beijing 100080, Peoples R China
英文摘要:
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 similar to -1/k(2) 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 -1/k(2) 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. (C) 2011 Elsevier B.V All rights reserved.
