  A Slave-Boson perturbational approach to ground-state properties of the
$U\to\infty$ periodic Anderson model is derived as an expansion around the
Atomic Limit ($V=0$). In the case of zero temperature any constraint-integral
or limiting procedure can be avoided, a gauge-symmetry broken Mean-Field phase
is not involved. Physical quantities like the wave vector $k$ dependent Green's
function obey a direct representation in Feynman-skeleton diagrams in
$k$-space. A self-consistent $1/N$-expansion is derived, and its relation to
the limit of infinite spatial dimension $d\to\infty$ is pointed out.
