Year: 2015
Type: article
Abstract: An exact analytic solution of self-similar equations is obtained for propagation of a strong shock in a flat expanding Friedman universe. The time and radial dependences of the density and velocity of the polytropic gas behind the shock wave are obtained. The shock velocity in the expanding medium decreases as ~t −1/5, slower than the shock velocity in the static uniform medium (~t −3/5), and its radius increases ~t 4/5, more rapidly than in a uniform non-gravitating medium (~t 2/5). So, the shock propagates in the direction of a decreasing density at a larger speed than in a static medium due to accelerating action of the decreasing density, even in the presence of self-gravity.
Source: Gravitation and Cosmology
Author: G. S. Bisnovatyi-Kogan
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1722200086