THE TIME EVOLUTION OF BIAS

We study the evolution of the bias factor b and the mass-galaxy correl ation coefficient r in a simple analytic model for galaxy formation an d the gravitational growth of clustering. The model shows that b and r can be strongly time dependent but tend to approach unity even if gal axy formation never ends as the gravitational growth of clustering deb iases the older galaxies. The presence of random fluctuations in the s ites of galaxy formation relative to the mass distribution can cause l arge and rapidly falling bias values at high redshift.