C perturbations of FRW models with a cosmological constant
KFKI Research Institute for Particle and Nuclear Physics, Budapest 114, PO Box 49, 1525, Hungary e-mail: [vasuth;czinner]@rmki.kfki.hu
2 Department of Physics, Umeå University, 90187 Umeå, Sweden e-mail: email@example.com
Accepted: 8 October 2004
Spatially homogeneous and isotropic cosmological models, with a perfect fluid matter source and non-vanishing cosmological constant, are studied. The equations governing linear perturbations of the space-time and the variation of energy density are given. The complete solution of the problem is obtained for perturbations, using a comoving time. The Sachs-Wolfe fluctuations of the temperature of the cosmic background radiation are obtained for the relatively growing density perturbations. It is found that the observable celestial microwave fluctuation pattern underwent a reversal approximately two billion years ago. What is observed today is a negative image of the last scattering surface with an attenuation of the fluctuations, due to the presence of the cosmological constant.
Key words: cosmology: cosmic microwave background / cosmology: large scale structure of Universe
© ESO, 2005