New cosmic accelerating scenario without dark energy

• Published in: Physical review. D, Particles, fields, gravitation, and cosmology Vol. 86; no. 10
• Main Authors: Lima, J. A. S., Basilakos, S., Costa, F. E. M.
• Format: Journal Article
• Language: English
• Published: 27-11-2012
• Subjects: Cosmological constant; Cosmology; Dark energy; Gravitation; Instability; Mathematical models; Statistical tests; Universe
• ISSN: 1550-7998; 1550-2368
• DOI: 10.1103/PhysRevD.86.103534

We propose an alternative, non-singular, cosmic scenario based on gravitationally induced particle production. The model is an attempt to evade the coincidence and cosmological constant problems of the standard model and also to connect the early and late time accelerating stages of the Universe. Our space-time emerges from a pure initial de Sitter stage thereby providing a natural solution to the horizon problem. Subsequently, due to an instability provoked by the production of mass-less particles, the Universe evolves smoothly to the standard radiation dominated era thereby ending the production of radiation as required by the conformal invariance. In this framework, we also compare the observed growth rate of clustering with that predicted by the current CCDM model. Performing a x[sup 2] statistical test we show that the CCDM model provides growth rates that match sufficiently well with the observed growth rate of structure.