Soft singularity crossing and transformation of matter properties

Understand

We investigate particular cosmological models, based either on tachyon fields or on perfect fluids, for which soft future singularities arise in a natural way.

• Our main result is the description of a smooth crossing of the soft singularity in models with an anti-Chaplygin gas or with a particular tachyon field in the presence of dust.
• Such a crossing is made possible by certain transformations of matter properties.
• Some of these cosmological evolutions involving tachyons are compatible with SNIa data.