Inverse phase transitions: Does baryogenesis lead to dark matter?

The phase structure of a field theory can have two qualitatively different forms- the less familiar of which involves high temperature symmetry breaking and low temperature symmetry restoration and is dubbed an inverse phase transition. After a general discussion of such inverse phase transitions, we present an application of this phenomenon in which the symmetry under consideration is baryon number. The model has the virtues of generating the observed quark-antiquark asymmetry (with no explicit baryon number violating interactions) while simultaneously providing the dark matter known to exist in galactic halos and clusters of galaxies. Constraints from cosmology and particle physics highly constrain the mass of this dark matter candidate: 40GeV less than m_phi less than 50GeV. In this way we demonstrate our main conclusion: the exotic phase structure of the inverted form can give rise to novel, predictive and testable cosmological phenomenon.