Master Thesis

CDM density perturbation today. Unfortunately the oscillation frequency increases for higher k-modes, requiring more
time-steps (see figure 6.6). More problematical is a strong growth of the perturbation variables at high k, shown in figure
6.5. Although the unusual behavior of V γ begins at about k=20h· M pc −1 , D gc grows only at higher k (k=110·hM pc −1 ).
The reason is that V γ has first to grow on the order of magnitude of D gc, before D gc is affected by V γ.
34 6.3 The Evolution of Perturbations