A Relativistic Interpretation of Bias in Newtonian Simulations
  Observables of cosmic structures are usually not the underlying matter field
but biased tracers of matter, such as galaxies or halos. We show how the bias
found in Newtonian N-body simulations can be interpreted in terms of the
weak-field limit of General Relativity (GR). For this we employ standard
Newtonian simulations of cold dark matter and incorporate GR/radiation via a
weak-field dictionary that we have recently developed. We find that even when a
simple local biasing scheme is employed in the Newtonian simulation, the
relativistic bias becomes inherently scale-dependent due to the presence of
radiation and GR corrections. This scale-dependence could be in principle
observed on large scales in upcoming surveys. As a working example, we apply
our methodology to Newtonian simulations for the spherical collapse and recover
permille-level agreement between the approaches for extracting the relativistic
bias on all considered scales.
