  We investigate galaxy clustering and galaxy-mass correlations in the LCDM
cosmological model using a large volume SPH simulation. For the most part, the
predicted biases between galaxies and dark matter lead to good agreement with
current observations, including: (1) a nearly constant comoving correlation
length from z=3 to z=0 for mass-selected galaxy samples of constant comoving
space density; (2) an rms bias factor b~1 at z=0; (3) a scale-dependent bias on
small scales that transforms the curved dark matter correlation function into a
nearly power-law galaxy correlation function; (4) galaxy pairwise dispersion
and hierarchical skewness ratio S_3 in good agreement with observed values, and
lower than values for the dark matter by ~20%; (5) a ratio of galaxy-galaxy to
galaxy-mass correlation functions consistent with recent measurements from the
RCS survey; and (6) a mean excess mass dM(260/h kpc) approximately proportional
to galaxy baryon mass M_b, in agreement with lensing estimates from the SDSS.
These clustering properties vary with galaxy baryon mass and, more strongly,
with stellar population age, in good qualitative agreement with the observed
dependence of galaxy clustering and galaxy-mass correlations on galaxy type.
The predicted ratio dM(260)/M_b is lower than the SDSS estimates for galaxies
with M_b>~2e11 Msun, but numerical resolution effects account for most of this
discrepancy, leaving little room for feedback or other astrophysical processes
to reduce the stellar masses of luminous galaxies, at least given our adopted
cosmological parameters. Our results show that the LCDM model and the galaxy
formation physics incorporated in the SPH simulation give a good account of
observed galaxy clustering, but anticipated improvements in clustering and weak
lensing measurements will soon test this picture in much more detail.
