Eur. Phys. J. C (2012) 72: 2149
https://doi.org/10.1140/epjc/s10052-012-2149-0

Regular Article - Theoretical Physics

Dark energy, matter creation and curvature

Departamento de Física y Astronomía, Facultad de Ciencias, Universidad de Valparaíso, Av. Gran Bretana 1111, Valparaíso, Chile

^* e-mail: victor@dfa.uv.cl

Received: 3 July 2012
Revised: 14 August 2012
Published online: 8 September 2012

Abstract

The most studied way to explain the current accelerated expansion of the universe is to assume the existence of dark energy; a new component that fills the universe, does not form clumps, currently dominates the evolution, and has a negative pressure. In this work I study an alternative model proposed by Lima et al. (Abramo and Lima in Class. Quantum Gravity 13:2953, 1996; Zimdahl in Phys. Rev. D 53:5483, 1996; Zimdahl and Pavón in Mon. Not. R. Astron. Soc. 266:872, 1994), which does not need an exotic equation of state, but assumes instead the existence of gravitational particle creation. Because this model fits the supernova observations as well as the ΛCDM model, I perform in this work a thorough study of this model, considering an explicit spatial curvature. I found that in this scenario we can alleviate the cosmic coincidence problem, basically showing that these two components, dark matter and dark energy, are of the same nature, but they act at different scales. I also shown the inadequacy of some particle creation models, and I study a previously proposed new model that overcomes these difficulties.