astrophysical twin universe and cosmology Ghost matter astrophysical matter.6. Spiral structure. (p2)
Fig.4 : Schematic representation of a galaxy confined in a hole, in the surrounding hot ghost matter.
In the figure, the border of the hole is abrupt. A more detailed image can be found in reference [22]. See figure 5.
Fig.5 : Schematic representation of a galaxy confined in a hole, in the surrounding hot ghost matter. Numerical result [22].
It seems quite difficult to deal with such a 3D problem with current systems. It would require a huge number of interacting mass points.
Let us consider the case of an unrealistic galaxy, confined by a ring. In order to build useful initial conditions, we will first introduce some theoretical tools.
