Strongly Coupled Cosmologies
  Models including an energy transfer from CDM to DE are widely considered in
the literature, namely to allow DE a significant high-z density. Strongly
Coupled cosmologies assume a much larger coupling between DE and CDM, together
with the presence of an uncoupled warm DM component, as the role of CDM is
mostly restricted to radiative eras. This allows us to preserve small scale
fluctuations even if the warm particle, possibly a sterile neutrino, is quite
light, O(100 eV). Linear theory and numerical simulations show that these
cosmologies agree with LCDM on supergalactic scales; e.g., CMB spectra are
substantially identical. Simultaneously, simulations show that they
significantly ease problems related to the properties of MW satellites and
cores in dwarfs. SC cosmologies also open new perspectives on early black hole
formation, and possibly lead towards unificating DE and inflationary scalar
fields.
