ETHOS - An Effective Theory of Structure Formation: From dark particle
  physics to the matter distribution of the Universe
  We formulate an effective theory of structure formation (ETHOS) that enables
cosmological structure formation to be computed in almost any microphysical
model of dark matter physics. This framework maps the detailed microphysical
theories of particle dark matter interactions into the physical effective
parameters that shape the linear matter power spectrum and the self-interaction
transfer cross section of non-relativistic dark matter. These are the input to
structure formation simulations, which follow the evolution of the cosmological
and galactic dark matter distributions. Models with similar effective
parameters in ETHOS but with different dark particle physics would nevertheless
result in similar dark matter distributions. We present a general method to map
an ultraviolet complete or effective field theory of low energy dark matter
physics into parameters that affect the linear matter power spectrum and carry
out this mapping for several representative particle models. We further propose
a simple but useful choice for characterizing the dark matter self-interaction
transfer cross section that parametrizes self-scattering in structure formation
simulations. Taken together, these effective parameters in ETHOS allow the
classification of dark matter theories according to their structure formation
properties rather than their intrinsic particle properties, paving the way for
future simulations to span the space of viable dark matter physics relevant for
structure formation.
