Could the cosmic acceleration be transient? A cosmographic evaluation

Autor(es)

Guimaraes, A. C. C. ^[1] ; Lima, J. A. S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Astron, BR-05508090 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Classical and Quantum Gravity; v. 28, n. 12 JUN 21 2011.
• Citações Web of Science: 39

Resumo

A possible slowing down of the cosmic expansion is investigated through a cosmographic approach. By expanding the luminosity distance to fourth order and fitting the SN Ia data from the most recent compilations (Union, Constitution and Union 2), the marginal likelihood distributions for the deceleration parameter today suggest a recent reduction of the cosmic acceleration and indicate that there is a considerable probability for q(0) > 0. Also in contrast to the prediction of the Lambda CDM model, the cosmographic q(z) reconstruction permits a cosmic expansion history where the cosmic acceleration could already have peaked and be presently slowing down, which would imply that the recent accelerated expansion of the universe is a transient phenomenon. It is also shown that to describe a transient acceleration the luminosity distance needs to be expanded at least to fourth order. The present cosmographic results depend neither on the validity of general relativity nor on the matter-energy contents of the universe. (AU)

• Processo FAPESP: 07/54915-9 - Investigação da distribuição de matéria escura através de seus efeitos como lentes gravitacionais
• Beneficiário: Antonio Candido de Camargo Guimarães Junior
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 04/13668-0 - Cosmologia na era da precisão: energia escura, matéria escura e radiação cósmica de fundo
• Beneficiário: Jose Ademir Sales de Lima
• Modalidade de apoio: Auxílio à Pesquisa - Temático