Vacuum pressure, dark energy and dark matter
  It has been argued that the correct, i.e. positive, sign of quantum vacuum
energy density, or more properly, negative sign of quantum vacuum pressure,
requires not a very large number, e.g. ~100, of additional, undiscovered
fundamental bosonic particle species, absent in the standard model.
Interpretation of the new particle species in terms of dark matter ones permits
to qualitatively, and even quantitatively, connect all the three concepts given
in the title.
