Abstract
The present accelerated expansion of the Universe has enriched the list of possible scenarios for its fate, singular or not. In this paper a unifying framework for analyzing such behaviors is proposed, based on generalized power and asymptotic expansions of the barotropic index , or equivalently of the deceleration parameter , in terms of the time coordinate. Besides well-known singular and nonsingular future behaviors, other types of strong singularities appear around the phantom divide in flat models, with features similar to those of big rip or big bang/crunch, which we have dubbed “grand rip” and “grand bang/crunch,” respectively, since energy density and pressure diverge faster than in coordinate time. In addition to this, the scale factor does not admit convergent generalized power series around these singularities with a finite number of terms with negative powers.
- Received 10 August 2014
DOI:https://doi.org/10.1103/PhysRevD.90.064014
© 2014 American Physical Society