  It is shown {\it in detail how} the ground-state self-energy
$\Sigma(k,\omega)$ of the spin-unpolarized uniform electron gas (with the
density parameter $r_s$) in its high-density limit $r_s\to 0 $ determines: the
momentum distribution $n(k)$ through the Migdal formula, the kinetic energy $t$
from $n(k)$, the potential energy $v$ through the Galitskii-Migdal formula, the
static structure factor $S(q)$ from $e=t+v$ by means of a Hellmann-Feynman
functional derivative. The ring-diagram partial summation or random-phase
approximation is extensively used and the results of Macke,
Gell-Mann/Brueckner, Daniel/Vosko, Kulik, and Kimball are summarized in a
coherent manner. There several identities were brought to the light.
