2010/05/31 by Roberto Casadio, A. Gruppuso, Alessandro Gruppuso · 17 citations
Mathematics · Physics and Astronomy · #Age of the universe #Anisotropy #Astrophysics #Cosmic background radiation #Cosmic microwave background #Cosmological constant #Cosmology #Cosmology and Gravitation Theories #Dark energy #Galaxies: Formation, Evolution, Phenomena #Lambda #Mathematics #Metric expansion of space #Physics #Quantum mechanics #Radio Astronomy Observations and Technology #Spectral density #Statistics #Theoretical physics #Universe #astro-ph.CO #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.84.023503
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 84(2) (American Physical Society) · 6 pages, 2 figures. Accepted for publication in Physical Review D
arxiv created 2011/06/18 · openalex publication_date 2011/07/05 · arxiv updated 2011/08/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We consider generalizations of the entropic accelerating universe recently proposed in [D. A. Easson, P. H. Frampton, and G. F. Smoot, Phys. Lett. B 696, 273 (2011).] and [D. A. Easson, P. H. Frampton, and G. F. Smoot, arXiv:1003.1528.] and show that their background equations can be made equivalent to a model with a dark energy component with a constant parameter of state wX=\ensuremath-1+2\ensuremathγ/3, where \ensuremathγ is related to the coefficients of the new terms in the Friedmann equations. After discussing all the Friedmann equations for an arbitrary \ensuremathγ, we show how to recover the standard scalings for dust and radiation. The acoustic scale \ensuremathℓA, related to the peak positions in the pattern of the angular power spectrum of the cosmic microwave background anisotropies, is also computed and yields the stringent bound |\ensuremathγ|\ensuremath≪1. We then argue that future data might be able to distinguish this model from pure \ensuremathΛCDM (corresponding to \ensuremathγ=0).