Observational constraints on higher order clustering up to z similar or equal to 1

We present constraints on the validity of the hierarchical gravitational in stability theory and the evolution of biasing based on measurements of high er order clustering statistics in the Deeprange Survey, a catalog of simila r to 710,000 galaxies with I-AB less than or equal to 24 derived from a Kit t Peak National Observatory (KPNO) 4 m CCD imaging survey of a contiguous 4 degrees x 4 degrees region. We compute the three- and four-point angular c orrelation functions using a direct estimation for the former and the count s-in-cells technique for both. The skewness, s(3), decreases by a factor of similar or equal to3-4 as galaxy magnitude increases over the range 17 les s than or equal to I less than or equal to 22.5 (0.1 less than or similar t o z less than or similar to 0.8). This decrease is consistent with a small increase of the bias with increasing redshift, but not by more than a facto r of 2 for the highest redshifts probed. Our results are strongly inconsist ent, at about the 3.5-4 sigma level, with typical cosmic string models in w hich the initial perturbations follow a non-Gaussian distribution; such mod els generally predict an opposite trend in the degree of bias as a function of redshift. We also find that the scaling relation between the three- and four-point correlation functions remains approximately invariant over the above magnitude range. The simplest model that is consistent with these con straints is a universe in which an initially Gaussian perturbation spectrum evolves under the influence of gravity combined with a low level of bias b etween the matter and the galaxies that decreases slightly from z similar t o0.8 to the current epoch.