2006/12/17 by M. Kunz, Martin Kunz, D. Sapone +1 · 5 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Particle physics theoretical and experimental studies #astro-ph #gr-qc #hep-ph
paper · pdf · doi:10.1103/physrevlett.98.121301
published as Phys.Rev.Lett.98:121301,2007 · 4 pages, 2 figures
arxiv created 2006/12/17 · openalex publication_date 2007/03/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
There is now strong observational evidence that the expansion of the Universe is accelerating. The standard explanation invokes an unknown "dark energy" component. But such scenarios are faced with serious theoretical problems, which has led to increased interest in models where instead general relativity is modified in a way that leads to the observed accelerated expansion. The question then arises whether the two scenarios can be distinguished. Here we show that this may not be so easy, demonstrating explicitly that a generalized dark energy model can match the growth rate of the Dvali-Gabadadze-Porrati model and reproduce the 3+1 dimensional metric perturbations. Cosmological observations are then unable to distinguish the two cases.