The self-similar evolution of holes in an Einstein-de Sitter universe
Abstract
Similarity solutions have been found for the nonlinear evolution of spherical holes in an Einstein-de Sitter universe. A negative perturbation grows until it becomes a hole, which expands in a self-similar fashion, in most cases sweeping up and compressing the matter around it into a thin, dense shell. Holes compensated by an overdense shell are considered, and it is shown that the Einstein-de Sitter-Sedov solution for a cosmological blast wave gives the self-similar adiabatic flow of a collisional gas around such a hole. The corresponding solution for a collisionless gas is given, followed by a solution for a collisional gas with omega much less than one. Uncompensated holes are treated, giving solutions for a collisionless gas, a collisional gas, and for a mixture where the collisionless gas dominates. The possibility that holes may form naturally from the growth of fluctuations in a hierarchical clustering model is examined. Several processes modifying the similarity solutions are discussed.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- May 1985
- DOI:
- 10.1086/191027
- Bibcode:
- 1985ApJS...58....1B
- Keywords:
-
- Cosmology;
- Galactic Clusters;
- Galactic Evolution;
- Hydrodynamics;
- Relativity;
- Shock Waves;
- Collisional Plasmas;
- Collisionless Plasmas;
- Density Distribution;
- Hubble Constant;
- Nonlinear Equations;
- Perturbation Theory;
- Similarity Theorem;
- Astrophysics