Tachyon cosmology, supernovae data and the Big Brake singularity

Abstract

We compare the existing observational data on type Ia Supernovae with the evolutions of the universe predicted by a one-parameter family of tachyon models which we have introduced recently in paper \cite{we-tach}. Among the set of the trajectories of the model which are compatible with the data there is a consistent subset for which the universe ends up in a new type of soft cosmological singularity dubbed Big Brake. This opens up yet another scenario for the future history of the universe besides the one predicted by the standard $Λ$CDM model.

v2: 8 pages, 1 figure + 2 figure panels of 6 figures each; slightly shortened for improved presentation; new references; published version