  The thermal Green function $D^{\mu\nu}(x)$ for free, massless gauge bosons is
computed exactly in a variety of gauges (Feynman, covariant, Coulomb, and
Landshoff-Rebhan). At large temporal separations it falls exponentially. At
large spatial separations it falls like $T/r$. In contrast, the
zero-temperature propagator falls quadratically in both regimes, being
proportional to $1/x^{2}$.
