The presence of the A0 condensate in quark-gluon plasma leads to Z(3) symmetry breaking and Furry's theorem violation. Due to this phenomenon the color charges are induced and other even-number diagrams are allowed. We calculate the first diagram of this series – tadpole diagram with one gluon line and find induced color charges in the plasma. Next, quark polarization operator in presence is calculated and partially investigated.
We present a (hopefully) novel calculation of the vacuum energy in expanding FLRW spacetimes based on the renormalization of quantum field theory in nonzero backgrounds. We compute the renormalized effective action up to the two-point function and then apply the formalism to the cosmological backgrounds of interest. As an example we calculate for quasi de Sitter spacetimes the leading correction to the vacuum energy given by the tadpole diagram and show that it behaves as [Formula: see text] where H0 is the Hubble constant and Λ P is the Planck constant. This is of the same order of magnitude as the observed dark energy density in the universe.
Induced charges and quark polarization operator at A0 background
