2001/06/29 by Izabela Jakacka, Jerzy Stelmach · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Geophysics and Gravity Measurements #astro-ph
paper · pdf · doi:10.1088/0264-9381/18/14/303
published as Class.Quant.Grav.18:2643-2658,2001 · 21 pages, 7 figures, corrected version of the paper published in Class. Quantum Grav. 18 (2001) 2643-2658
openalex publication_date 2001/06/29 · arxiv created 2008/02/15 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
A class of spherically symmetric Stephani cosmological models is examined in the context of evolution type. It is assumed that the equation of state at the symmetry centre of the models is barotropic ( p ( t ) = αρ( t )) and the function k ( t ) playing the role of spatial curvature is proportional to the Stephani version of the Friedmann-Robertson-Lemaître-Walker scale factor R ( t ) ( k ( t ) = β R ( t )). A classification of the cosmological models is performed depending on different values and signs of parameters α and β. It is shown that for β<0 (hyperbolic geometry) a dust-like (α = 0) cosmological model exhibits accelerated expansion at later stages of evolution. The Hubble and deceleration parameters are defined in the model and it is shown that the deceleration parameter decreases with the distance becoming negative for sufficiently distant galaxies. The redshift-magnitude relation m ( z ) is calculated and discussed in the context of SnIa observational data. It is noted that the most distant supernovae of type Ia fit quite well to the relation m ( z ) calculated in the considered model ( H 0 = 65 km s -1 Mpc -1 , Ω 0 ⩽0.3) without introducing the cosmological constant. It is also shown that the age of the universe in the model is longer than in the Friedmann model corresponding to the same H 0 and Ω 0 parameters.