No-Scale SU(5) Super-GUTs
  We reconsider the minimal SU(5) Grand Unified Theory (GUT) in the context of
no-scale supergravity, assuming that the soft supersymmetry-breaking parameters
satisfy universality conditions at some input scale M_in above the GUT scale
M_GUT. When setting up such a no-scale super-GUT model, special attention must
be paid to avoiding the Scylla of rapid proton decay and the Charybdis of an
excessive density of cold dark matter, while also having an acceptable mass for
the Higgs boson. We do not find consistent solutions if none of the matter and
Higgs fields are assigned to twisted chiral supermultiplets, even in the
presence of Giudice-Masiero terms. However, consistent solutions may be found
if at least one fiveplet of GUT Higgs fields is assigned to a twisted chiral
supermultiplet, with a suitable choice of modular weights. Spin-independent
dark matter scattering may be detectable in some of these consistent solutions.
