http://arxiv.org/abs/1910.01651
Bimetric gravity can reproduce the accelerated expansion of the Universe, without a cosmological constant. However, the stability of these solutions to linear perturbations has been questioned, suggesting exponential growth of structure in this approximation. We present a simple model of structure formation, for which an analytic solution is derived. The solution is well-behaved, showing that there is no physical instability with respect to these perturbations. The model can yield a growth of structure exhibiting measurable differences from $\Lambda$CDM.
M. Högås, F. Torsello and E. Mörtsell
Tue, 8 Oct 19
34/88
Comments: 15 pages, 7 figures