The Initial State of a Primordial Anisotropic Stage of Inflation

Understand

We investigate the possibility that the inflationary period in the early universe was preceded by a primordial stage of strong anisotropy.

• In particular we focus on the simplest model of this kind, where the spacetime is described by a non-singular Kasner solution that quickly evolves into an isotropic de Sitter space, the so-called Kasner-de Sitter solution.
• The initial Big Bang singularity is replaced, in this case, by a horizon.
• We show that the extension of this metric to the region behind the horizon contains a timelike singularity which will be visible by cosmological observers.