Gravity, bias, and the galaxy three-point correlation function

One uncertainty in our picture of the Universe is whether galaxies are a fair or biased representation of the distribution of mass in the Universe. I show that dependence of the galaxy three-point correlation function on configuration shape can be used to separate the contributions of gravitational clustering and nonlinear bias. This allows a determination of the amount of bias in the galaxy distribution that is independent of the slowing of growth of fluctuations in an open universe, unavoidably mixed in determinations using peculiar velocities. Application to the Lick Observatory catalog gives a bias parameter b=3.03±0.65.