English

New Agegraphic Dark Energy in Brans-Dicke Theory

Cosmology and Nongalactic Astrophysics 2014-11-20 v1

Abstract

In this paper, we investigate the new agegraphic dark energy model in the framework of Brans-Dicke theory which is a natural extension of the Einstein's general relativity. In this framework the form of the new agegraphic dark energy density takes as ρq=3n2Φ(t)η2\rho_{q} =3n^2 \Phi(t)\eta^{-2}, where η\eta is the conformal age of the universe and Φ(t)\Phi(t) is the Brans-Dicke scalar field representing the inverse of the time-variable Newton's constant. We derive the equation of state of the new agegraphic dark energy and the deceleration parameter of the universe in the Brans-Dicke theory. It is very interesting to find that in the Brans-Dicke theory the agegraphic dark energy realizes quintom-like behavior, i.e., its equation of state crosses the phantom divide w=1w=-1 during the evolution. We also compare the situation of the agegraphic dark energy model in the Brans-Dicke theory with that in the Einstein's theory. In addition, we discuss the new agegraphic dark energy model with interaction in the framework of the Brans-Dicke theory.

Keywords

Cite

@article{arxiv.0909.4911,
  title  = {New Agegraphic Dark Energy in Brans-Dicke Theory},
  author = {Xiang-Lai Liu and Xin Zhang},
  journal= {arXiv preprint arXiv:0909.4911},
  year   = {2014}
}

Comments

15 pages, 4 figures