  We use high-resolution dissipationless simulations of the concordance flat
LCDM model to make predictions for the galaxy--mass (GM) correlations and
compare them to the recent SDSS weak lensing measurements.We use a simple
observationally motivated scheme to assign luminosities and colors to the
halos.This allows us to closely match the selection criteria used to define
observational samples.The simulations reproduce the observed GM correlation
function and its observed dependencies on luminosity and color.The luminosity
dependence of the correlation function is primarily determined by the changing
relative contribution of central and satellite galaxies at different
luminosities. The color dependence of the GM correlations reflects the
difference in the typical environments of blue and red galaxies. We also find
agreement between the predicted and observed cross-bias, b_x=b/r,at all probed
scales.The GM correlation coefficient, r, is close to unity on scales >1/h
Mpc.The cross bias is thus expected to measure the actual bias of galaxy
clustering on these scales.The aperture mass-to-light ratio is independent of
galaxy color.The aperture mass scales approximately linearly with luminosity at
L_r>10^{10}h^{-2} Lsun, while at lower luminosities the scaling is shallower:
L_r^{0.5}. We show that most of the luminous galaxies (M_r<-21) are near the
centers of their halos and their GM correlation function at r<100/h kpc can
therefore be interpreted as the average dark matter density profile of these
galaxies. We find that for galaxies in a given narrow luminosity range, there
is a broad and possibly non-gaussian distribution of halo virial masses.
Therefore, the average relation between mass and luminosity derived from the
weak lensing analyses should be interpreted with caution.
