The spectrum of density perturbations in an expanding universe.
Abstract
The basic dynamic equations that govern the evolution of perturbations in a Friedmann-Lemaitre universe are derived. General solutions describing the evolution of adiabatic perturbations in the density of matter are obtained, and the choice of the appropriate initial conditions is examined. The various perturbation modes are compared, and the effects of decoupling on the perturbation spectrum are studied. The scheme used to follow the evolution of density perturbations through decoupling is based on an extension of the Eddington approximation to the radiative transfer equation, and is strictly valid in both optically thick and thin limits.
- Publication:
-
Confrontation of Cosmological Theories with Observational Data
- Pub Date:
- 1974
- Bibcode:
- 1974IAUS...63..175S
- Keywords:
-
- Adiabatic Conditions;
- Big Bang Cosmology;
- Perturbation Theory;
- Density Distribution;
- Free Electrons;
- Galactic Evolution;
- Metric Space;
- Optical Thickness;
- Radiative Transfer;
- Spectrum Analysis;
- Spherical Harmonics;
- Astrophysics