We present new measurements of the redshift-space three-point correlation function ( 3PCF ) of Luminous Red Galaxies ( LRGs ) from the Sloan Digital Sky Survey ( SDSS ) .
Using the largest dataset to date , the Data Release 7 ( DR7 ) LRGs , and an improved binning scheme compared to previous measurements , we measure the LRG 3PCF on large scales up to \sim 90 ~ { } h ^ { -1 } \mathrm { Mpc } , from the mildly non-linear to quasi-linear regimes .
Comparing the LRG correlations to the dark matter two- and three-point correlation functions , obtained from N-body simulations we infer linear and non-linear bias parameters .
As expected , LRGs are highly biased tracers of large scale structure , with a linear bias b _ { 1 } \sim 2 ; the LRGs also have a large positive non-linear bias parameter , in agreement with predictions of galaxy population models .
The use of the 3PCF to estimate biasing helps to also make estimates of the cosmological parameter \sigma _ { 8 } , as well as to infer best-fit parameters of the Halo Occupation Distribution parameters for LRGs .
We also use a large suite of public mock catalogs to characterize the error covariance matrix for the 3PCF and compare the variance among simulation results with jackknife error estimates .