The early universe could feature multiple reheating events, leading to
increases in the visible sector entropy density that dilute both
particle asymmetries and the number density of frozen-out states. I
will highlight that an important consequence of late time dilution is
that a smaller dark matter annihilation cross section is needed to
obtain the observed relic density, thus weakening experimental bounds
and also permitting superheavy dark matter. Moreover, I will outline a
new general dark matter scenario in which freeze-out occurs whilst the
energy density of the universe is dominated by a decoupled
non-relativistic species. Notably, decoupling during matter domination
changes the freeze-out dynamics, since the Hubble rate is
parametrically different for matter and radiation domination.
Furthermore, for successful Big Bang Nucleosynthesis the state
dominating the early universe energy density must decay, this dilutes
(or repopulates) the dark matter. Finally, I will highlight the
possibility of superheavy asymmetric dark matter models, made possible
by a sizeable entropy injection after dark matter freeze-out, which
have interesting astrophysical consequences.