  We discuss a two-point particle irreducible (2PPI) approach to many-body
physics which relies on a renormalization group (RG) flow equation for the
associated effective action. In particular, the general structure and
properties of this RG flow equation are analyzed in detail. Moreover, we
discuss how our 2PPI RG approach relates to Density Functional Theory and argue
that it can in principle be used to study ground-state properties of
non-relativistic many-body systems from microscopic interactions, such as
(heavy) nuclei. For illustration purposes, we use our formalism to compute the
ground-state properties of two toy models.
