Disformal Dark Matter
  We generalize dark matter production to a two-metric framework whereby the
physical metric, which couples to the Standard Model (SM), is conformally
and/or disformally related to the metric governing the gravitational dynamics.
We show that this setup is naturally present in many Ultra Violet (UV)
constructions, from K\"ahler moduli fields to tensor-portal models, and from
emergent gravity to supergravity models. In this setting we study dark matter
production in the early Universe resulting from both scatterings off the
thermal bath and the radiative decay of the inflaton. We also take into account
non-instantaneous reheating effects at the end of inflation. In this context,
dark matter emerges from the production of the scalar field mediating the
conformal/disformal interactions with the SM, i.e. realising a Feebly
Interacting Matter Particle (FIMP) scenario where the suppression scale of the
interaction between the scalar and the SM can be taken almost as high as the
Planck scale in the deep UV.
