New Gravitational Scales in Cosmological Surveys
  In the quasistatic regime, generic modifications to gravity can give rise to
novel scale-dependence of the gravitational field equations. Crucially, the
detectability of the new scale-dependent terms hinges upon the existence of an
effective mass scale or length scale at which corrections to General Relativity
become relevant. Starting from only a few basic principles, we derive the
general form of this scale-dependence. Our method recovers results previously
known in the specific case of Horndeski gravity, but also shows that they are
valid more generally, beyond the regime of scalar field theories. We forecast
the constraints that upcoming experiments will place on the existence of a new
fundamental mass scale or length scale in cosmology.
