  Astronomical observations reveal a gap in the mass spectrum of relativistic
objects: neither black holes nor neutron stars with 2 - 5 solar masses have
ever been observed.
  In this article I proceed in presenting the scenario which discloses a
possible hidden connection between massive neutron stars (MANSs), dark matter
and dark energy in cosmology. Accordingly, when the curved spacetime embedding
MANSs compresses the nuclear matter to beyond a critical supranuclear density
$n_{cr},$ mesons, generally transmitting the residual nuclear forces between
neutrons, could gain energy by frequently interacting with a scalar field
$\phi$ at the background. When the effective energy of mesons becomes
comparable to the bag energy enclosing the quarks, the neutrons merge together
and form a super-baryon (SB), whose interior is made of incompressible
gluon-quark superfluid. It turns out that the process has a runaway-character:
it enables the super-baryon to grow in mass and volume from inside-to-outside
to finally metamorphose the entire object into a completely invisible dark
gluon-quark object, practically indistinguishable from isolated stellar black
holes. The inability of these objects to merge with other objects whilst
agglomerating in clusters makes them excellent candidates both for black holes
and for dark matter halos in cosmology.
