Eur. Phys. J. C (2018) 78: 183
https://doi.org/10.1140/epjc/s10052-018-5677-4

Regular Article - Theoretical Physics

The cosmological dark sector as a scalar σ-meson field

¹ Instituto de Física Gleb Wataghin, UNICAMP, 13083-970, Campinas, SP, Brazil
² Instituto de Física, Universidade Federal da Bahia, 40210-340, Salvador, BA, Brazil

^* e-mail: saulo.carneiro@pq.cnpq.br

Received: 18 December 2017
Accepted: 22 February 2018
Published online: 5 March 2018

Abstract

Previous quantum field estimations of the QCD vacuum in the expanding space-time lead to a dark energy component scaling linearly with the Hubble parameter, which gives the correct figure for the observed cosmological term. Here we show that this behaviour also appears at the classical level, as a result of the chiral symmetry breaking in a low energy, effective -model. The dark sector is described in a unified way by the condensate and its fluctuations, giving rise to a decaying dark energy and a homogeneous creation of non-relativistic dark particles. The creation rate and the future asymptotic de Sitter horizon are both determined by the mass scale.