Non-Canonical Volume-Form Formulation of Modified Gravity Theories and
  Cosmology
  A concise description is presented of the basic features of the formalism of
non-canonical spacetime volume-forms and its application in modified gravity
theories and cosmology. The well known unimodular gravity theory appears as a
very special case. Concerning the hot issues facing cosmology now, we
specifically briefly outline the construction of: (a) unified description of
dark energy and dark matter as manifestations of a single material entity -- a
special scalar field "darkon"; (b) quintessential models of universe evolution
with a gravity-"inflaton"-assisted dynamical Higgs mechanism -- dynamical
suppression/generation of spontaneous electroweak gauge symmetry breaking in
the "early"/"late" universe; (c) unification of dark energy and dark matter
with diffusive interaction among them; (d) mechanism for suppression of 5-th
force without fine-tuning.
