We continue our work on a proposal for what dark matter could be, namely that the dark matter
consists of essentially macorscopic objects built from ordinary matter. The only element of “new
physics” is that there should exist several types or phases of vacuum. Then the dark matter
particles are bubbles of a new type of vacuum filled with ordinary matter - say diamond - under
high pressure and the whole bubble is supposedly contaminated by the materials in the extra
galactic or intragalactic space able to form dust. The dust has a lower than dimension 3 structure
and may well be long chains of atoms.
We begin speculations on identifying the phase transition between the vacua, which we require
in our model, with a (second order?) transition revealed in the Columbia plot with quark masses
as axes. In the corner of small quark masses there is a true phase transition as temperature is
raised, while outside this region there is instead no genuine phase transition under variation of the
temperature but rather only a “cross over”.