Structure of the gluon propagator at finite temperature

The thermal self-energy of gluons generally depends on four Lorentz-invariant functions. Only two of these occur in the hard thermal loop approximation of Braaten and Pisarski because of the abelian Ward identity KμΠ μν htl = 0. However, for the exact self-energy KμΠ μν 6= 0. In linear gauges the SlavnovTaylor identity is shown to require a non-linear relation among three of the Lorentz-invariant self-energy function: (ΠC) 2 = (K −ΠL)ΠD. This reduces the exact gluon propagator to a simple form containing only two types of poles: one that determines the behavior of transverse electric and magnetic gluons and one that controls the longitudinally polarized electric gluons. 11.10.Wx, 12.38.Mh, 25.75.+r Typeset using REVTEX 1