The small and the beautiful: How the star formation law affects galactic
  disk structure
  We investigate the influence of different analytical parameterizations and
fit functions for the local star formation rate in AMR simulations of an
isolated disk galaxy with the Nyx code. Such parameterizations express the star
formation efficiency as function of the local turbulent Mach number and virial
parameter. By employing the method of adaptively refined large eddy
simulations, we are able to evaluate these physical parameters from the
numerically unresolved turbulent energy associated with the grid scale. We
consider both single and multi free-fall variants of star formation laws
proposed by Padoan & Nordlund, Hennebelle & Chabrier, and Krumholz & McKee,
summarised and tested recently with numerical simulations by Federrath &
Klessen. We find that the global star formation rate and the relation between
the local star formation rate and the gas column density is reproduced in
agreement with observational constraints by all multi free-fall models of star
formation. Some models with obsolete calibration or a single free-fall time
scale, however, result in an overly clumpy disk that does not resemble the
structure of observed spirals.
