2007/11/30 by P. P. Avelino, L. M. G. beça, L. M. G. Beça +1
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics #Black Holes and Theoretical Physics #Chaplygin gas #Cosmology #Cosmology and Gravitation Theories #Dark energy #Dark fluid #Dark matter #Energy (signal processing) #Geophysics and Gravity Measurements #Instability #Lambda #Nonlinear system #Physics #Quantum mechanics #Standard Model (mathematical formulation) #Statistical physics #Theoretical physics #Type (biology) #astro-ph
paper · pdf · doi:10.1103/physrevd.77.063515
published as Phys. Rev. D77:063515,2008 · 6 pages, accepted for publication in Physical Review D
arxiv created 2008/02/01 · openalex publication_date 2008/03/12 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We revisit the paradigm of unified dark energy discussing in detail the averaging problem in this type of scenario, highlighting the need for a full nonlinear treatment. We also address the question of if and how models with one or several dark fluids can be observationally distinguished. Simpler and physically clearer derivations of some key results, most notably on the relation between the generalized Chaplygin gas and the standard (\ensuremathΛCDM) ``concordance'' model and on a Jeans-type small-scale instability of some coupled dark energy/dark matter models are presented.