  The implementation of the linear covariant gauge on the lattice faces a
conceptual problem: using the standard compact discretization, the gluon field
is bounded, while the four-divergence of the gluon field satisfies a Gaussian
distribution, i.e. it is unbounded. This can give rise to convergence problems
when a numerical implementation is attempted. In order to overcome this
problem, one can use different discretizations for the gluon field or consider
an SU(N_c) group with sufficiently large N_c. One can also consider small
values of the gauge parameter xi and study numerically the limiting case of xi
\to 0, i.e. the Landau gauge. These different approaches will be discussed
here.
