Eur. Phys. J. Plus (2016) 131: 163
https://doi.org/10.1140/epjp/i2016-16163-x

Regular Article

QCD nature of dark energy at finite temperature: Cosmological implications

¹ Department of Physics, Doğuş University, Acıbadem Kadıköy, 34722, Istanbul, Turkey
² Department of Physics, Boğaziçi University, 34342 Bebek, Istanbul, Turkey
³ Feza Gürsey Center for Physics and Mathematics, Boğaziçi University, 34684, Çengelköy, Istanbul, Turkey

^* e-mail: kazizi@dogus.edu.tr

Received: 9 October 2015
Revised: 25 February 2016
Accepted: 20 April 2016
Published online: 24 May 2016

Abstract

The Veneziano ghost field has been proposed as an alternative source of dark energy, whose energy density is consistent with the cosmological observations. In this model, the energy density of the QCD ghost field is expressed in terms of QCD degrees of freedom at zero temperature. We extend this model to finite temperature to search the model predictions from late time to early universe. We depict the variations of QCD parameters entering the calculations, dark energy density, equation of state, Hubble and deceleration parameters on temperature from zero to a critical temperature. We compare our results with the observations and theoretical predictions existing at different eras. It is found that this model safely defines the universe from quark condensation up to now and its predictions are not in tension with those of the standard cosmology. The EoS parameter of dark energy is dynamical and evolves from -1/3 in the presence of radiation to -1 at late time. The finite temperature ghost dark energy predictions on the Hubble parameter well fit to those of CDM and observations at late time.