Gravitational Lens Effect on the Cosmic Background Radiation Due to Nonlinear Inhomogeneities : Astrophysics and Relativity

概要

論文の詳細を見る
Null geodesic equations are numerically solved, in order to investigate the light propagation in inhomogeneous cosmological models. The models are derived using the N body simulation method and assuming for simplicity that clusters of galaxies are regarded as particles. Statistical properties of angular fluctuations of light paths and angular correlation functions of the cosmic background radiation are studied. It is shown that the angular fluctuations due to gravitational lensing depend much on the average particle size r and the correlation angle θ_c of the intrinsic density perturbations at the recombination epoch. If r is equal to or smaller than the size of the Coma cluster and θ_c≲5 arcmin, the lens effect may play a role to decrease the finite-beam-smeared temperature fluctuations of the cosmic background radiation by about 20%, compared with those in the no-lens case, while the non-smeared temperature fluctuations are enhanced for angles ≲8 arcmin. If r is larger than the above size and θ_c is equal to about 8 arcmin consistent with the most prevailing cosmological models, however, the lens effect is very small. Moreover it is shown that the dispersion of the fluctuations in different directions is not small, so that the fluctuations may be considerable in a special direction, and that the dependence of the fluctuations on the spatial correlation of particles is small.
理論物理学刊行会の論文
1989-09-25