Dark energy and QCD instanton vacuum in Friedmann-Lemaitre-Robertson-Walker universe

Abstract: The standard model of the universe, lambdaCDM, is based on the Friedmann-Lemaitre-Robertson-Walker metric with flat 3-dim coordinate space and Friedmann equations. The cosmological constant lambda is providing the cancellations of the matter fields contributions in the flat space. The dynamical dark energy is appearing on over of the vacuum energy of matter fields at the flat space. Within the Standard Model the gluon Yang-Mills (YM) fields are playing the special role since specific properties of their vacuum, where the presence of the gluon condensate, provide the flat space nonperturbative vacuum energy. It is natural to apply the successful instanton liquid model (ILM) of the QCD vacuum and its lowest excitations. Our aim is to calculate the gluon YM fields contribution to the dark energy density. The result of the calculations is corresponding lambdaCDM. We find the equation-of-state parameters w_0=-1, w_a=0 in accordance with lambdaCDM, while the newest data give them at least in the range -0.91 <w_0< -0.73, -1.05< w_a <-0.65 requesting non-acceptable value of scalar glueball mass m to be very small and comparable with present value of Hubble constant H0.