2014/02/28 by Spyros Basilakos, Joan Solà, Joan Sola · 1 citation
Physics and Astronomy · #Acceleration #Astrophysics #Black Holes and Theoretical Physics #Classical mechanics #Constant (computer programming) #Cosmological constant #Cosmology #Cosmology and Gravitation Theories #Dark energy #Dark matter #Energy density #Entropic force #Galaxies: Formation, Evolution, Phenomena #Hubble's law #Perturbation (astronomy) #Physics #Quantum mechanics #Statistical physics #Term (time) #Theoretical physics #Vacuum energy #astro-ph.CO #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.90.023008
published as Phys. Rev. D 90, 023008 (2014) · 11 pages, 1 figure accepted for publication by Physical Review D
arxiv created 2014/05/21 · openalex publication_date 2014/07/09 · arxiv updated 2014/07/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We reconsider the entropic-force model in which both kinds of Hubble terms, \stackrel\ifmmode \else \textperiodcentered \fiH and H2, appear in the effective dark energy (DE) density affecting the evolution of the main cosmological functions, namely, the scale factor, deceleration parameter, matter density, and growth of linear matter perturbations. However, we find that the entropic-force model is not viable at the background and perturbation levels due to the fact that the entropic formulation does not add a constant term in the Friedmann equations. On the other hand, if on mere phenomenological grounds we replace the \stackrel\ifmmode \else \textperiodcentered \fiH dependence of the effective DE density with a linear term H without including a constant additive term, we find that the transition from deceleration to acceleration becomes possible, but the recent structure formation data strongly disfavor this cosmological scenario. Finally, we briefly compare the entropic-force models with some related DE models (based on dynamical vacuum energy) which overcome these difficulties and are compatible with the present observations.