Halo clustering and g_{NL}-type primordial non-Gaussianity
  A wide range of multifield inflationary models generate non-Gaussian initial
conditions in which the initial adiabatic fluctuation is of the form (zeta_G +
g_{NL} zeta_G^3). We study halo clustering in these models using two different
analytic methods: the peak-background split framework, and brute force
calculation in a barrier crossing model, obtaining agreement between the two.
We find a simple, theoretically motivated expression for halo bias which agrees
with N-body simulations and can be used to constrain g_{NL} from observations.
We discuss practical caveats to constraining g_{NL} using only observable
properties of a tracer population, and argue that constraints obtained from
populations whose observed bias is <~ 2.5 are generally not robust to
uncertainties in modeling the halo occupation distribution of the population.
