Attractor behaviour in ELKO cosmology
Abstract
We study the dynamics of ELKO in the context of accelerated phase of our universe. To avoid the fine tuning problem associated with the initial conditions, it is required that the dynamical equations lead to an early-time attractor. In the earlier works, it was shown that the dynamical equations containing ELKO fields do not lead to early-time stable fixed points. In this work, using redefinition of variables, we show that ELKO cosmology admits early-time stable fixed points. More interestingly, we show that ELKO cosmology admit two sets of attractor points corresponding to slow and fast-roll inflation. The fast-roll inflation attractor point is unique for ELKO as it is independent of the form of the potential. We also discuss the plausible choice of interaction terms in these two sets of attractor points and constraints on the coupling constant.
- Publication:
-
Journal of Cosmology and Astroparticle Physics
- Pub Date:
- April 2013
- DOI:
- 10.1088/1475-7516/2013/04/025
- arXiv:
- arXiv:1212.3445
- Bibcode:
- 2013JCAP...04..025B
- Keywords:
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- Astrophysics - Cosmology and Nongalactic Astrophysics;
- High Energy Physics - Phenomenology;
- High Energy Physics - Theory
- E-Print:
- 13 pages, 1 figure