Abstract
The evolution of the spectrum of cosmological fluctuations from one cycle to the next is studied. It is pointed out that each cycle leads to a reddening of the spectrum. This opens up new ways to generate a scale-invariant spectrum of curvature perturbations. The large increase in the amplitude of the fluctuations quickly leads to a breakdown of the linear theory. More generally, we see that, after including linearized cosmological perturbations, a cyclic universe cannot be truly cyclic.
- Received 5 June 2009
DOI:https://doi.org/10.1103/PhysRevD.80.023535
©2009 American Physical Society