Empirical Validation of the Ising Galaxy Bias Model
  Repp and Szapudi (2019) present a physically-motivated galaxy bias model
which remains physical in low-density regions and which also provides a better
fit to simulation data than do typical survey-analysis bias models. Given
plausible simplifying assumptions, the physics of this model (surprisingly)
proves to be analogous to the Ising model of statistical mechanics. In the
present work we present a method of testing this Ising bias model against
empirical galaxy survey data. Using this method, we compare our model (as well
as three reference models -- linear, quadratic, and logarithmic) to SDSS,
6dFGS, and COSMOS2015 results, finding that for spectroscopic redshift surveys,
the Ising bias model provides a superior fit compared to the reference models.
Photometric redshifts, on the other hand, introduce enough error into the
radial coordinate that none of the models yields a good fit. A physically
meaningful galaxy bias model is necessary for optimal extraction of
cosmological information from dense galaxy surveys such as Euclid and WFIRST.
