Unification of Dark Matter and Dark Energy in a Modified Entropic Force Model
Abstract
In Verlinde's entropic force scenario of gravity, Newton's laws and Einstein equations can be obtained from the first principles and general assumptions. However, the equipartition law of energy is invalid at very low temperatures. We show clearly that the threshold of the equipartition law of energy is related with horizon of the universe. Thus, a onedimensional Debye (ODD) model in the direction of radius of the modified entropic force (MEF) may be suitable in description of the accelerated expanding universe. We present a Friedmann cosmic dynamical model in the ODDMEF framework. We examine carefully constraints on the ODDMEF model from the Union2 compilation of the Supernova Cosmology Project (SCP) collaboration, the data from the observation of the largescale structure (LSS) and the cosmic microwave background (CMB), i.e. SNe Ia+LSS+CMB. The combined numerical analysis gives the bestfit value of the model parameters ζ ≃ 10^{9} and Ω_{m0} = 0.224, with χ^{2}_{min} = 591.156. The corresponding age of the universe agrees with the result of D. Spergel et al. [J.M. Bardeen, B. Carter, and S.W. Hawking, Commun. Math. Phys. 31 (1973) 161] at 95% confidence level. The numerical result also yields an accelerated expanding universe without invoking any kind of dark energy. Taking ζ(≡ 2πω_{D}/H_{0}) as a running parameter associated with the structure scale r, we obtain a possible unified scenario of the asymptotic flatness of the radial velocity dispersion of spiral galaxies, the accelerated expanding universe and the Pioneer 10/11 anomaly in the entropic force framework of Verlinde.
 Publication:

Communications in Theoretical Physics
 Pub Date:
 July 2011
 DOI:
 10.1088/02536102/56/1/32
 arXiv:
 arXiv:1009.1506
 Bibcode:
 2011CoTPh..56..184C
 Keywords:

 General Relativity and Quantum Cosmology;
 Astrophysics  Cosmology and Extragalactic Astrophysics
 EPrint:
 23 pages, 6 figures