  Monte-Carlo simulations of abelian projection in $T \neq 0$ pure lattice QCD
show that
  1)\ Polyakov loops written in terms of abelian link fields alone play a role
of an order parameter of deconfinement transition
  2)\ the abelian Polyakov loops are decomposed into contributions from Dirac
strings of monopoles and from photons
  3)\ vanishing of the abelian Polyakov loops in the confinement phase is due
to the Dirac strings alone and the photons give a finite contribution in both
phases.
  Moreover, these results appear to hold good in unitary gauges. This suggests
that monopole condensation as the color confinement mechanism is gauge
independent.
