Slow-roll k-essence

Details Slow-roll k-essence Slow-roll k-essence

2009-06-03

arxiv.org/abs/0906.0628v3

Phys.Rev.D80:043517,2009

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

7 pages and 5 figures, typos corrected

Scientific paper

10.1103/PhysRevD.80.043517

We derive slow-roll conditions for thawing k-essence with a separable Lagrangian $p(X,\phi)=F(X)V(\phi)$. We examine the evolution of the equation of state parameter, $w$, as a function of the scale factor $a$, for the case where $w$ is close to -1. We find two distinct cases, corresponding to $X \approx 0$ and $F_X \approx 0$, respectively. For the case where $X\approx0$ the evolution of $\phi$ and hence $w$ is described by only two parameters, and $w(a)$ is model-independent and coincides with similar behavior seen in thawing quintessence models. This result also extends to non-separable Lagrangians where $X\approx0$. For the case $F_X \approx 0$, an expression is derived for $w(a)$, but this expression depends on the potential $V(\phi)$, so there is no model-independent limiting behavior. For the $X \approx 0$ case, we derive observational constraints on the two parameters of the model, $w_0$ (the present-day value of $w$), and the $K$, which parametrizes the curvature of the potential. We find that the observations sharply constrain $w_0$ to be close to -1, but provide very poor constraints on $K$.

Affiliated with

Also associated with

No associations

Rating

Slow-roll k-essence does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Slow-roll k-essence, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Slow-roll k-essence will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-193463