Can Assembly Bias Explain the Lensing Amplitude of the BOSS CMASS Sample
  in a Planck Cosmology?
  In this paper, we investigate whether galaxy assembly bias can reconcile the
20-40% disagreement between the observed galaxy projected clustering signal and
the galaxy-galaxy lensing signal in the BOSS CMASS galaxy sample reported in
Leauthaud et al. (2017). We use the suite of AbacusCosmos Lamda-CDM simulations
at Planck best-fit cosmology and two flexible implementations of extended halo
occupation distribution (HOD) models that incorporate galaxy assembly bias to
build forward models and produce joint fits of the observed galaxy clustering
signal and the galaxy-galaxy lensing signal. We find that our models using the
standard HODs without any assembly bias generalizations continue to show a
20-40% over-prediction of the observed galaxy-galaxy lensing signal. We find
that our implementations of galaxy assembly bias do not reconcile the two
measurements at Planck best-fit cosmology. In fact, despite incorporating
galaxy assembly bias, the satellite distribution parameter, and the satellite
velocity bias parameter into our extended HOD model, our fits still strongly
suggest a 31-34% discrepancy between the observed projected clustering and
galaxy-galaxy lensing measurements. It remains to be seen whether a combination
of other galaxy assembly bias models, alternative cosmological parameters, or
baryonic effects can explain the amplitude difference between the two signals.
