  This work develops and explores a quantum-based theory which enables the
nature and origin of cold dark matter (CDM) to be understood without need to
introduce exotic particles. The quantum approach predicts the existence of
certain macroscopic quantum structures that are WIMP-like even when occupied by
traditional baryonic particles. These structures function as dark matter
candidates for CDM theory on large scales where it has been most successful,
and retain the potential to yield observationally compliant predictions on
galactic cluster and sub-cluster scales. Relatively pure, high angular
momentum, eigenstate solutions obtained from Schrodinger's equation in weak
gravity form the structural basis. They have no classical analogue, and
properties radically different from those of traditional localised matter
(whose eigenstate spectra contain negligible quantities of such states).
Salient features include radiative lifetimes that can exceed the age of the
universe, energies and 'sizes' consistent with galactic halos, and negligible
interaction rates with radiation and macroscopic galactic objects. This
facilitates the formation of sparsely populated macroscopic quantum structures
that are invisible and stable. Viable structure formation scenarios are based
on the seed potential wells of primordial black holes formed at the e+/e- phase
transition. The structures can potentially produce suitable internal density
distributions and have capacity to accommodate the required amount of halo dark
matter. The formation scenarios show that it is possible to incorporate
structures into universal evolutionary scenarios without significantly
compromising the results of WMAP or the measurements of elemental BBN ratios.
