EDP Sciences
Free access
Volume 390, Number 3, August II 2002
Page(s) 809 - 815
Section Cosmology
DOI http://dx.doi.org/10.1051/0004-6361:20020746

A&A 390, 809-815 (2002)
DOI: 10.1051/0004-6361:20020746

Deflationary $\Lambda(t)$ cosmology: Observational expressions

J. V. Cunha, J. A. S. Lima and N. Pires

Departamento de Física, Universidade Federal do Rio Grande do Norte, CP 1641, 59072-970 Natal, RN, Brasil

(Received 23 January 2002 / Accepted 15 May 2002)

We discuss the classical cosmological tests for a large class of FRW type models driven by a decaying vacuum energy density. Analytic expressions for the lookback time, age of the universe, luminosity distance, angular diameter, and galaxy number counts versus redshift are derived and their meaning discussed in detail. It is found that the standard cold dark matter (CDM) results are significantly altered, showing that such tests may constrain appreciably the physical parameters of these models which are also in agreement with the accelerated expansion suggested by the latest SNe type Ia observations. Cosmology: decaying vacuum, kinematic tests

Key words: cosmology: observations -- cosmology: theory -- cosmology: distance scale

Offprint request: J. A. S. Lima, limajas@dfte.ufrn.br

© ESO 2002