The large-scale structure in the universe is believed to have arisen out of small, random density perturbations generated in the very early universe that are amplified by gravity. Large and usually intricate N-body simulations are typically employed to model the complex nonlinear dynamics in a self-gravitating medium. We suggest a very simple model that predicts, on large scales, the correct density and velocity distributions. The model does not involve an explicit computation of the gravitational force. It is based on a simple transformation of the variables and local conservation laws of mass and generalized linear momentum. The model demonstrates that the overall appearance of large-scale structure in the universe is explicitly determined by the initial velocity field, and it reveals the most significant large-scale effects of gravity on the formation of structure.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science