Instability in a minimal bimetric gravity model

  title={Instability in a minimal bimetric gravity model},
  author={Frank Konnig and Luca Amendola},
We discuss in detail a particularly simple example of a bimetric massive gravity model which seems to offer an alternative to the standard cosmological model at background level. For small redshifts, its equation of state is $w(z)\approx-1.22_{-0.02}^{+0.02}-0.64_{-0.04}^{+0.05}z/(1+z)$. Just like $\Lambda$CDM, it depends on a single parameter, has an analytical background expansion law and fits the expansion cosmological data well. However, confirming previous results, we find that the model… CONTINUE READING