2008/01/01 by Joshua A. Frieman, Paulo Pellegrini, Simone Daflon +2 · 6 citations
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Relativity and Gravitational Theory #astro-ph.CO
paper · pdf · doi:10.1063/1.3000000
published as AIP Conf.Proc.1057:87-124,2008 · 36 pages, 11 figures, based on 5 lectures given at XII Ciclo de Cursos Especiais at Observatorio Nacional, Rio de Janeiro, Brazil, 1-5 Oct. 2007
openalex publication_date 2008/01/01 · arxiv created 2009/04/12 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/29
The discovery ten years ago that the expansion of the Universe is accelerating put in place the present cosmological model, in which the Universe is composed of 4% baryons, 20% dark matter, and 76% dark energy. Yet the underlying cause of cosmic acceleration remains a mystery: it could arise from the repulsive gravity of dark energy—for example, the quantum energy of the vacuum—or it may signal that General Relativity breaks down on cosmological scales and must be replaced. In these lectures, I present the observational evidence for cosmic acceleration and what it has revealed about dark energy, discuss a few of the theoretical ideas that have been proposed to explain acceleration, and describe the key observational probes that we hope will shed light on this enigma in the coming years. Based on five lectures given at the XII Ciclo de Cursos Especiais at the Observatorio Nacional, Rio de Janeiro, Brazil, 1–5 October 2007.