New tracker models of dark energy
Abstract
We describe a new class of dark energy (DE) models which behave like cosmological trackers at early times. These models are based on the α-attractor set of potentials, originally discussed in the context of inflation. The new models allow the current acceleration of the universe to be reached from a wide class of initial conditions. Prominent examples of this class of models are the potentials coth(varphi) and cosh(varphi). A remarkable feature of this new class of models is that they lead to large enough negative values of the equation of state at the present epoch, consistent with the observations of accelerated expansion of the universe, from a very large initial basin of attraction. They therefore avoid the fine tuning problem which afflicts many models of DE.
- Publication:
-
Journal of Cosmology and Astroparticle Physics
- Pub Date:
- August 2018
- DOI:
- 10.1088/1475-7516/2018/08/009
- arXiv:
- arXiv:1709.09193
- Bibcode:
- 2018JCAP...08..009B
- Keywords:
-
- General Relativity and Quantum Cosmology;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- High Energy Physics - Phenomenology;
- High Energy Physics - Theory
- E-Print:
- 24 pages, 16 figures, matches published version in JCAP