  It is conjectured that dark matter (DM) was produced before inflation from
neutral particles present after the Big Bang and survived inflation due to a
specific coupling with gravitation, while the charged particles existing after
the Big Bang disappeared during inflation in a process of charge
non-conservation. Ordinary matter was produced at a later stage at a lower
temperature following a symmetry restoring phase transition. In this way the
non-luminous character of dark matter and the existence of two types of matter,
ordinary and dark, get a natural explanation. Because of the high temperatures
preceding inflation, the masses of particles produced during that time are too
large to be detected by conventional particle physics methods and possibly will
never be detected.
