A bimetric gravity model with a variable speed of light is shown to be in agreement with the results reported from the Planck satellite in 2013 .
The predicted scalar mode spectral index is n _ { s } \approx 0.96 and its running is \alpha _ { s } \approx 8 \times 10 ^ { -4 } when the fundamental length scale \ell _ { 0 } in the model is fixed to be \ell _ { 0 } \approx 10 ^ { 5 } \ell _ { P } , where \ell _ { P } is the Planck length \ell _ { P } = 1.62 \times 10 ^ { -33 } { cm } , giving the observed CMB fluctuations : \delta _ { H } \approx 10 ^ { -5 } .
The enlarged lightcone ensures that horizon and flatness problems are solved .
The model is free from many of the fine-tuning problems of the inflationary models and the fluctuations that form the seeds of structure formation do not lead to a chaotic inhomogeneous universe and the need for a multiverse .